diff --git a/backtrace-library/src/androidTest/java/backtraceio/library/ApplicationMetadataTest.java b/backtrace-library/src/androidTest/java/backtraceio/library/ApplicationMetadataTest.java
new file mode 100644
index 00000000..ca4e0727
--- /dev/null
+++ b/backtrace-library/src/androidTest/java/backtraceio/library/ApplicationMetadataTest.java
@@ -0,0 +1,48 @@
+package backtraceio.library;
+
+import static org.junit.Assert.assertEquals;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.platform.app.InstrumentationRegistry;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import backtraceio.library.common.ApplicationMetadataCache;
+
+@RunWith(AndroidJUnit4.class)
+public class ApplicationMetadataTest {
+    private Context context;
+
+    @Before
+    public void setUp() {
+        context = InstrumentationRegistry.getInstrumentation().getContext();
+        // prepare instance
+        ApplicationMetadataCache.getInstance(context);
+    }
+
+    @Test
+    public void shouldCorrectlyRetrieveApplicationName() {
+        ApplicationMetadataCache cache = ApplicationMetadataCache.getInstance(context);
+        assertEquals(cache.getApplicationName(), context.getOpPackageName());
+    }
+
+    @Test
+    public void shouldCorrectlyRetrieveApplicationPackageName() {
+        ApplicationMetadataCache cache = ApplicationMetadataCache.getInstance(context);
+        assertEquals(cache.getPackageName(), context.getOpPackageName());
+    }
+
+    @Test
+    public void shouldCorrectlyRetrieveApplicationVersion() throws PackageManager.NameNotFoundException {
+        ApplicationMetadataCache cache = ApplicationMetadataCache.getInstance(context);
+        PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getOpPackageName(), 0);
+        assertEquals(cache.getApplicationVersion(), String.valueOf(packageInfo.versionCode));
+    }
+
+}
diff --git a/backtrace-library/src/androidTest/java/backtraceio/library/BacktraceClientUniqueEventTest.java b/backtrace-library/src/androidTest/java/backtraceio/library/BacktraceClientUniqueEventTest.java
index af44bff8..ad6a15d0 100644
--- a/backtrace-library/src/androidTest/java/backtraceio/library/BacktraceClientUniqueEventTest.java
+++ b/backtrace-library/src/androidTest/java/backtraceio/library/BacktraceClientUniqueEventTest.java
@@ -400,48 +400,4 @@ public void uniqueEventUpdateAttributes() {
 
         assertEquals(expectedValue, backtraceClient.metrics.getUniqueEvents().getLast().getAttributes().get(expectedKey));
     }
-
-    @Test
-    public void uniqueEventEmptyAttributeValueShouldNotOverridePreviousValueOnUpdate() {
-        backtraceClient.metrics.enable(new BacktraceMetricsSettings(credentials, defaultBaseUrl, 0));
-
-        String expectedKey = "foo";
-        String expectedValue = "bar";
-
-        backtraceClient.attributes.put(expectedKey, expectedValue);
-        assertTrue(backtraceClient.metrics.addUniqueEvent(uniqueAttributeName[0]));
-
-        assertEquals(uniqueAttributeName[0], backtraceClient.metrics.getUniqueEvents().getLast().getName());
-        assertEquals(expectedValue, backtraceClient.metrics.getUniqueEvents().getLast().getAttributes().get(expectedKey));
-
-        backtraceClient.attributes.put(expectedKey, "");
-        assertEquals("", backtraceClient.attributes.get(expectedKey));
-
-        // Force update
-        backtraceClient.metrics.send();
-
-        assertEquals(expectedValue, backtraceClient.metrics.getUniqueEvents().getLast().getAttributes().get(expectedKey));
-    }
-
-    @Test
-    public void uniqueEventNullAttributeValueShouldNotOverridePreviousValueOnUpdate() {
-        backtraceClient.metrics.enable(new BacktraceMetricsSettings(credentials, defaultBaseUrl, 0));
-
-        String expectedKey = "foo";
-        String expectedValue = "bar";
-
-        backtraceClient.attributes.put(expectedKey, expectedValue);
-        assertTrue(backtraceClient.metrics.addUniqueEvent(uniqueAttributeName[0]));
-
-        assertEquals(uniqueAttributeName[0], backtraceClient.metrics.getUniqueEvents().getLast().getName());
-        assertEquals(expectedValue, backtraceClient.metrics.getUniqueEvents().getLast().getAttributes().get(expectedKey));
-
-        backtraceClient.attributes.put(expectedKey, null);
-        assertNull(backtraceClient.attributes.get(expectedKey));
-
-        // Force update
-        backtraceClient.metrics.send();
-
-        assertEquals(expectedValue, backtraceClient.metrics.getUniqueEvents().getLast().getAttributes().get(expectedKey));
-    }
 }
diff --git a/backtrace-library/src/androidTest/java/backtraceio/library/metrics/BacktraceMetricsTest.java b/backtrace-library/src/androidTest/java/backtraceio/library/metrics/BacktraceMetricsTest.java
index f7e46145..d4b3b7ba 100644
--- a/backtrace-library/src/androidTest/java/backtraceio/library/metrics/BacktraceMetricsTest.java
+++ b/backtrace-library/src/androidTest/java/backtraceio/library/metrics/BacktraceMetricsTest.java
@@ -57,7 +57,7 @@ public void setUp() {
     @Test
     public void addAttributesSummedEvent() {
         SummedEvent summedEvent = new SummedEvent(summedEventName, null);
-        Map<String, Object> attributes = new HashMap<String, Object>() {{
+        Map<String, String> attributes = new HashMap<String, String>() {{
             put("foo", "bar");
         }};
         summedEvent.addAttributes(attributes);
@@ -67,7 +67,7 @@ public void addAttributesSummedEvent() {
     @Test
     public void addAttributesUniqueEvent() {
         UniqueEvent uniqueEvent = new UniqueEvent(uniqueAttributeName[0], null);
-        Map<String, Object> attributes = new HashMap<String, Object>() {{
+        Map<String, String> attributes = new HashMap<String, String>() {{
             put("foo", "bar");
         }};
         uniqueEvent.update(BacktraceTimeHelper.getTimestampSeconds(), attributes);
diff --git a/backtrace-library/src/main/java/backtraceio/library/common/ApplicationMetadataCache.java b/backtrace-library/src/main/java/backtraceio/library/common/ApplicationMetadataCache.java
new file mode 100644
index 00000000..34637180
--- /dev/null
+++ b/backtrace-library/src/main/java/backtraceio/library/common/ApplicationMetadataCache.java
@@ -0,0 +1,102 @@
+package backtraceio.library.common;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+
+import backtraceio.library.logger.BacktraceLogger;
+
+public class ApplicationMetadataCache {
+
+    private static final transient String LOG_TAG = ApplicationMetadataCache.class.getSimpleName();
+
+    private static volatile ApplicationMetadataCache instance;
+
+    /**
+     * Cached application name
+     */
+    private String applicationName;
+
+    /**
+     * Cached application version
+     */
+    private String applicationVersion;
+
+    /**
+     * Cached package name
+     */
+    private String packageName;
+
+    private final Context context;
+
+    private ApplicationMetadataCache(Context context) {
+        this.context = context;
+    }
+
+    /**
+     * Returns current application cache. This instance is a singleton since we can only operate
+     * in a single application scope.
+     *
+     * @param context Application context
+     * @return Application metadata cache
+     */
+    public static ApplicationMetadataCache getInstance(Context context) {
+        if (instance == null) {
+            synchronized (ApplicationMetadataCache.class) {
+                if (instance == null) {
+                    instance = new ApplicationMetadataCache(context);
+                }
+            }
+        }
+        return instance;
+    }
+
+    /**
+     * Retrieves application name from context. The name will be cached over checks
+     *
+     * @return application name
+     */
+    public String getApplicationName() {
+        if (!BacktraceStringHelper.isNullOrEmpty(applicationName)) {
+            return applicationName;
+        }
+
+        applicationName = context.getApplicationInfo().loadLabel(context.getPackageManager()).toString();
+        return applicationName;
+    }
+
+    /**
+     * Retrieves application version from the context. If the version name is not defined, the version code will be used instead.
+     *
+     * @return current application version.
+     */
+    public String getApplicationVersion() {
+        if (!BacktraceStringHelper.isNullOrEmpty(applicationVersion)) {
+            return applicationVersion;
+        }
+        try {
+            PackageInfo info = context.getPackageManager()
+                    .getPackageInfo(context.getPackageName(), 0);
+            applicationVersion = BacktraceStringHelper.isNullOrEmpty(info.versionName) ? String.valueOf(info.versionCode) : info.versionName;
+
+            return applicationVersion;
+        } catch (PackageManager.NameNotFoundException e) {
+            BacktraceLogger.e(LOG_TAG, "Could not resolve application version", e);
+            return "";
+        }
+    }
+
+    /**
+     * Retrieves package name from the context.
+     *
+     * @return current package name.
+     */
+    public String getPackageName() {
+        if (!BacktraceStringHelper.isNullOrEmpty(packageName)) {
+            return packageName;
+        }
+        packageName = context.getApplicationContext().getPackageName();
+
+        return packageName;
+    }
+}
diff --git a/backtrace-library/src/main/java/backtraceio/library/common/DeviceAttributesHelper.java b/backtrace-library/src/main/java/backtraceio/library/common/DeviceAttributesHelper.java
index 046c6651..63b6100d 100644
--- a/backtrace-library/src/main/java/backtraceio/library/common/DeviceAttributesHelper.java
+++ b/backtrace-library/src/main/java/backtraceio/library/common/DeviceAttributesHelper.java
@@ -19,7 +19,7 @@
 import android.text.TextUtils;
 
 import java.io.BufferedReader;
-import java.io.InputStreamReader;
+import java.io.FileReader;
 import java.util.HashMap;
 import java.util.UUID;
 
@@ -36,6 +36,11 @@
 public class DeviceAttributesHelper {
     private final Context context;
 
+    /*
+     * Current Device id
+     */
+    private static String uuid;
+
     public DeviceAttributesHelper(Context context) {
         this.context = context;
     }
@@ -61,15 +66,17 @@ public HashMap<String, String> getDeviceAttributes(Boolean includeDynamicAttribu
         result.put("device.cpu.temperature", String.valueOf(getCpuTemperature()));
         result.put("device.is_power_saving_mode", String.valueOf(isPowerSavingMode()));
         result.put("device.wifi.status", getWifiStatus().toString());
-        result.put("system.memory.total", getMaxRamSize());
-        result.put("system.memory.free", getDeviceFreeRam());
-        result.put("system.memory.active", getDeviceActiveRam());
         result.put("app.storage_used", getAppUsedStorageSize());
         result.put("battery.level", String.valueOf(getBatteryLevel()));
         result.put("battery.state", getBatteryState().toString());
         result.put("cpu.boottime", String.valueOf(java.lang.System.currentTimeMillis() - android.os.SystemClock
                 .elapsedRealtime()));
 
+
+        ActivityManager.MemoryInfo memoryInfo = getMemoryInformation();
+        result.put("system.memory.total", Long.toString(memoryInfo.totalMem));
+        result.put("system.memory.free", Long.toString(memoryInfo.availMem));
+        result.put("system.memory.active", Long.toString(memoryInfo.totalMem - memoryInfo.availMem));
         return result;
     }
 
@@ -144,14 +151,14 @@ private BluetoothStatus isBluetoothEnabled() {
     private float getCpuTemperature() {
         Process p;
         try {
-            p = Runtime.getRuntime().exec("cat sys/class/thermal/thermal_zone0/temp");
-            p.waitFor();
-            BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
 
+            BufferedReader reader = new BufferedReader(new FileReader("/sys/class/thermal/thermal_zone0/temp"));
             String line = reader.readLine();
             if (line == null) {
                 return 0.0f;
             }
+            reader.close();
+
             return Float.parseFloat(line) / 1000.0f;
         } catch (Exception e) {
             return 0.0f;
@@ -255,33 +262,20 @@ private BatteryState getBatteryState() {
      * @return unique device identifier
      */
     private String generateDeviceId() {
-        String androidId = Settings.Secure.getString(this.context.getContentResolver(),
-                Settings.Secure.ANDROID_ID);
-
-        if (TextUtils.isEmpty(androidId)) {
-            return null;
+        if (!BacktraceStringHelper.isNullOrEmpty(uuid)) {
+            return uuid;
         }
 
-        return UUID.nameUUIDFromBytes(androidId.getBytes()).toString();
-    }
-
-    /**
-     * Get RAM size of current device
-     * available from API 16
-     *
-     * @return device RAM size
-     */
-    private String getMaxRamSize() {
-        return Long.toString(getMemoryInformation().totalMem);
-    }
+        String androidId = Settings.Secure.getString(this.context.getContentResolver(),
+                Settings.Secure.ANDROID_ID);
 
-    private String getDeviceFreeRam() {
-        return Long.toString(getMemoryInformation().availMem);
-    }
+        // if the android id is not defined we want to cache at least guid 
+        // for the current session
+        uuid = TextUtils.isEmpty(androidId)
+                ? UUID.randomUUID().toString()
+                : UUID.nameUUIDFromBytes(androidId.getBytes()).toString();
 
-    private String getDeviceActiveRam() {
-        ActivityManager.MemoryInfo mi = getMemoryInformation();
-        return Long.toString(mi.totalMem - mi.availMem);
+        return uuid;
     }
 
     private ActivityManager.MemoryInfo getMemoryInformation() {
diff --git a/backtrace-library/src/main/java/backtraceio/library/models/attributes/ReportDataAttributes.java b/backtrace-library/src/main/java/backtraceio/library/models/attributes/ReportDataAttributes.java
new file mode 100644
index 00000000..889c82d1
--- /dev/null
+++ b/backtrace-library/src/main/java/backtraceio/library/models/attributes/ReportDataAttributes.java
@@ -0,0 +1,27 @@
+package backtraceio.library.models.attributes;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class ReportDataAttributes {
+    private final Map<String, String> reportAttributes = new HashMap<>();
+
+    private final Map<String, Object> reportAnnotations = new HashMap<>();
+
+
+    public void addAnnotation(String key, Object value) {
+        reportAnnotations.put(key, value);
+    }
+
+    public void addAttribute(String key, String value) {
+        reportAttributes.put(key, value);
+    }
+
+    public Map<String, String> getAttributes() {
+        return reportAttributes;
+    }
+
+    public Map<String, Object> getAnnotations() {
+        return reportAnnotations;
+    }
+}
diff --git a/backtrace-library/src/main/java/backtraceio/library/models/attributes/ReportDataBuilder.java b/backtrace-library/src/main/java/backtraceio/library/models/attributes/ReportDataBuilder.java
new file mode 100644
index 00000000..b6922ce2
--- /dev/null
+++ b/backtrace-library/src/main/java/backtraceio/library/models/attributes/ReportDataBuilder.java
@@ -0,0 +1,53 @@
+package backtraceio.library.models.attributes;
+
+import java.util.Map;
+
+import backtraceio.library.common.TypeHelper;
+
+public class ReportDataBuilder {
+
+    /**
+     * Divide custom user attributes into primitive and complex attributes and add to this object. By default null values will be included.
+     *
+     * @param attributes client's attributes
+     * @return Report data attributes divided into attributes and annotations
+     */
+    public static ReportDataAttributes getReportAttributes(Map<String, Object> attributes) {
+        return getReportAttributes(attributes, false);
+    }
+
+    /**
+     * Divide custom user attributes into primitive and complex attributes and add to this object
+     *
+     * @param attributes client's attributes
+     * @param skipNull   define attributes behavior on null value. By default all null values
+     *                   will be included in the report. For some features like metrics, we don't want to send
+     *                   null values, because they can generate invalid behavior/incorrect information.
+     * @return Report data attributes divided into attributes and annotations
+     */
+    public static ReportDataAttributes getReportAttributes(Map<String, Object> attributes, boolean skipNull) {
+        ReportDataAttributes reportDataAttributes = new ReportDataAttributes();
+
+        if (attributes == null) {
+            return reportDataAttributes;
+        }
+
+        for (Map.Entry<String, Object> entry : attributes.entrySet()) {
+            String key = entry.getKey();
+            Object value = entry.getValue();
+            if (value == null) {
+                if (!skipNull) {
+                    reportDataAttributes.addAttribute(key, null);
+                }
+                continue;
+            }
+            if (TypeHelper.isPrimitiveOrPrimitiveWrapperOrString(value.getClass())) {
+                reportDataAttributes.addAttribute(key, value.toString());
+            } else {
+                reportDataAttributes.addAnnotation(key, value);
+            }
+        }
+
+        return reportDataAttributes;
+    }
+}
diff --git a/backtrace-library/src/main/java/backtraceio/library/models/json/BacktraceAttributes.java b/backtrace-library/src/main/java/backtraceio/library/models/json/BacktraceAttributes.java
index de9d247c..ad03bd9b 100644
--- a/backtrace-library/src/main/java/backtraceio/library/models/json/BacktraceAttributes.java
+++ b/backtrace-library/src/main/java/backtraceio/library/models/json/BacktraceAttributes.java
@@ -1,7 +1,6 @@
 package backtraceio.library.models.json;
 
 import android.content.Context;
-import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.os.Build;
 import android.provider.Settings;
@@ -15,18 +14,17 @@
 import java.util.UUID;
 
 import backtraceio.library.BacktraceClient;
+import backtraceio.library.common.ApplicationMetadataCache;
 import backtraceio.library.common.BacktraceStringHelper;
 import backtraceio.library.common.DeviceAttributesHelper;
-import backtraceio.library.common.TypeHelper;
 import backtraceio.library.enums.ScreenOrientation;
-import backtraceio.library.logger.BacktraceLogger;
+import backtraceio.library.models.attributes.ReportDataAttributes;
+import backtraceio.library.models.attributes.ReportDataBuilder;
 
 /**
  * Class instance to get a built-in attributes from current application
  */
 public class BacktraceAttributes {
-    private static final transient String LOG_TAG = BacktraceAttributes.class.getSimpleName();
-
     /**
      * Get built-in primitive attributes
      */
@@ -42,15 +40,10 @@ public class BacktraceAttributes {
      */
     private final Context context;
 
-    /**
-     * Are metrics enabled?
-     */
-    private static boolean isMetricsEnabled = false;
-
     /**
      * Metrics session ID
      */
-    private static String sessionId = UUID.randomUUID().toString();
+    private final static String sessionId = UUID.randomUUID().toString();
 
     /**
      * Create instance of Backtrace Attribute
@@ -76,7 +69,7 @@ public BacktraceAttributes(Context context, BacktraceReport report, Map<String,
             this.setExceptionAttributes(report);
         }
         if (clientAttributes != null) {
-            this.convertClientAttributes(clientAttributes);
+            this.convertAttributes(clientAttributes);
         }
         if (report != null && clientAttributes != null) {
             BacktraceReport.concatAttributes(report, clientAttributes);
@@ -110,10 +103,10 @@ private void setDeviceInformation(Boolean includeDynamicAttributes) {
     }
 
     private void setAppInformation() {
-        this.attributes.put("application.package", this.context.getApplicationContext()
-                .getPackageName());
-        this.attributes.put("application", getApplicationName());
-        String version = getApplicationVersionOrEmpty();
+        ApplicationMetadataCache applicationMetadata = ApplicationMetadataCache.getInstance(this.context);
+        this.attributes.put("application.package", applicationMetadata.getPackageName());
+        this.attributes.put("application", applicationMetadata.getApplicationName());
+        String version = applicationMetadata.getApplicationVersion();
         if (!BacktraceStringHelper.isNullOrEmpty(version)) {
             // We want to standardize application.version attribute name
             this.attributes.put("application.version", version);
@@ -188,15 +181,6 @@ private int getScreenBrightness() {
                 0);
     }
 
-    /**
-     * Divide client attributes into primitive and complex attributes and add to this object
-     *
-     * @param clientAttributes client's attributes
-     */
-    private void convertClientAttributes(Map<String, Object> clientAttributes) {
-        convertAttributes(clientAttributes);
-    }
-
     /**
      * Divide report attributes into primitive and complex attributes and add to this object
      *
@@ -211,41 +195,15 @@ private void convertReportAttributes(BacktraceReport report) {
         }
     }
 
-    /**
-     * Divide custom user attributes into primitive and complex attributes and add to this object
-     *
-     * @param attributes client's attributes
-     */
-    private void convertAttributes(Map<String, Object> attributes) {
-        for (Map.Entry<String, Object> entry : attributes.entrySet()) {
-            Object value = entry.getValue();
-            if (value == null) {
-                continue;
-            }
-            Class type = value.getClass();
-            if (TypeHelper.isPrimitiveOrPrimitiveWrapperOrString(type)) {
-                this.attributes.put(entry.getKey(), value.toString());
-            } else {
-                this.complexAttributes.put(entry.getKey(), value);
-            }
+    private void convertAttributes(Map<String, Object> clientAttributes) {
+        if (clientAttributes == null || clientAttributes.isEmpty()) {
+            return;
         }
+        ReportDataAttributes data = ReportDataBuilder.getReportAttributes(clientAttributes);
+        this.attributes.putAll(data.getAttributes());
+        this.complexAttributes.putAll(data.getAnnotations());
     }
 
-    public String getApplicationName() {
-        return this.context.getApplicationInfo().loadLabel(this.context
-                .getPackageManager()).toString();
-    }
-
-    public String getApplicationVersionOrEmpty() {
-        try {
-            return this.context.getPackageManager()
-                    .getPackageInfo(this.context.getPackageName(), 0).versionName;
-        } catch (PackageManager.NameNotFoundException e) {
-            BacktraceLogger.e(LOG_TAG, "Could not resolve application version");
-            e.printStackTrace();
-        }
-        return "";
-    }
 
     public Map<String, Object> getAllAttributes() {
         Map<String, Object> attributes = new HashMap<String, Object>();
diff --git a/backtrace-library/src/main/java/backtraceio/library/models/metrics/Event.java b/backtrace-library/src/main/java/backtraceio/library/models/metrics/Event.java
index fce15e6e..6c475a5f 100644
--- a/backtrace-library/src/main/java/backtraceio/library/models/metrics/Event.java
+++ b/backtrace-library/src/main/java/backtraceio/library/models/metrics/Event.java
@@ -12,8 +12,11 @@ public abstract class Event {
     @SerializedName("timestamp")
     protected long timestamp;
 
+    /**
+     * The event should always have attributes. Event without attributes won't be processed
+     */
     @SerializedName("attributes")
-    protected Map<String, Object> attributes;
+    protected Map<String, String> attributes = new HashMap<>();
 
     public Event(long timestamp) {
         this.timestamp = timestamp;
@@ -23,30 +26,16 @@ public long getTimestamp() {
         return this.timestamp;
     }
 
-    public Map<String, Object> getAttributes() {
+    public Map<String, String> getAttributes() {
         return this.attributes;
     }
 
     public abstract String getName();
 
-    protected void addAttributesImpl(Map<String, Object> attributes) {
-        if (attributes == null || attributes.size() == 0) {
+    protected void addAttributesImpl(Map<String, String> attributes) {
+        if (attributes == null || attributes.isEmpty()) {
             return;
         }
-
-        Map<String, Object> attributesNoEmpty = new HashMap<String, Object>();
-
-        for (String key : attributes.keySet()) {
-            Object value = attributes.get(key);
-            if (BacktraceStringHelper.isObjectNotNullOrNotEmptyString(value)) {
-                attributesNoEmpty.put(key, value);
-            }
-        }
-
-        if (this.attributes == null) {
-            this.attributes = attributesNoEmpty;
-        } else {
-            this.attributes.putAll(attributesNoEmpty);
-        }
+        this.attributes.putAll(attributes);
     }
 }
diff --git a/backtrace-library/src/main/java/backtraceio/library/models/metrics/EventsPayload.java b/backtrace-library/src/main/java/backtraceio/library/models/metrics/EventsPayload.java
index 05198c75..f07d9241 100644
--- a/backtrace-library/src/main/java/backtraceio/library/models/metrics/EventsPayload.java
+++ b/backtrace-library/src/main/java/backtraceio/library/models/metrics/EventsPayload.java
@@ -33,5 +33,13 @@ public void setDroppedEvents(int droppedEvents) {
         this.eventsMetadata.setDroppedEvents(droppedEvents);
     }
 
+    public String getApplicationVersion() {
+        return appVersion;
+    }
+
+    public String getApplicationName() {
+        return application;
+    }
+
     public abstract ConcurrentLinkedDeque<T> getEvents();
 }
diff --git a/backtrace-library/src/main/java/backtraceio/library/models/metrics/SummedEvent.java b/backtrace-library/src/main/java/backtraceio/library/models/metrics/SummedEvent.java
index b9665f01..bcd8efb8 100644
--- a/backtrace-library/src/main/java/backtraceio/library/models/metrics/SummedEvent.java
+++ b/backtrace-library/src/main/java/backtraceio/library/models/metrics/SummedEvent.java
@@ -13,14 +13,14 @@ public final class SummedEvent extends Event {
     private final String name;
 
     public SummedEvent(String name) {
-        this(name, new HashMap<String, Object>());
+        this(name, null);
     }
 
-    public SummedEvent(String name, Map<String, Object> attributes) {
+    public SummedEvent(String name, Map<String, String> attributes) {
         this(name, BacktraceTimeHelper.getTimestampSeconds(), attributes);
     }
 
-    public SummedEvent(String name, long timestamp, Map<String, Object> attributes) {
+    public SummedEvent(String name, long timestamp, Map<String, String> attributes) {
         super(timestamp);
         this.name = name;
         addAttributesImpl(attributes);
@@ -35,7 +35,7 @@ public String getName() {
         return this.name;
     }
 
-    public void addAttributes(Map<String, Object> attributes) {
+    public void addAttributes(Map<String, String> attributes) {
         addAttributesImpl(attributes);
     }
 }
diff --git a/backtrace-library/src/main/java/backtraceio/library/models/metrics/UniqueEvent.java b/backtrace-library/src/main/java/backtraceio/library/models/metrics/UniqueEvent.java
index 789b9825..151bbe93 100644
--- a/backtrace-library/src/main/java/backtraceio/library/models/metrics/UniqueEvent.java
+++ b/backtrace-library/src/main/java/backtraceio/library/models/metrics/UniqueEvent.java
@@ -22,14 +22,14 @@ public class UniqueEvent extends Event {
     private final List<String> name;
 
     public UniqueEvent(String name) {
-        this(name, new HashMap<String, Object>());
+        this(name, null);
     }
 
-    public UniqueEvent(String name, Map<String, Object> attributes) {
+    public UniqueEvent(String name, Map<String, String> attributes) {
         this(name, BacktraceTimeHelper.getTimestampSeconds(), attributes);
     }
 
-    public UniqueEvent(String name, long timestamp, Map<String, Object> attributes) {
+    public UniqueEvent(String name, long timestamp, Map<String, String> attributes) {
         super(timestamp);
         this.name = new ArrayList<String>() {{
             add(name);
@@ -49,7 +49,7 @@ public String getName() {
         return "";
     }
 
-    public void update(long timestamp, Map<String, Object> attributes) {
+    public void update(long timestamp, Map<String, String> attributes) {
         this.timestamp = timestamp;
         addAttributesImpl(attributes);
     }
diff --git a/backtrace-library/src/main/java/backtraceio/library/services/BacktraceEventsHandler.java b/backtrace-library/src/main/java/backtraceio/library/services/BacktraceEventsHandler.java
index 50e6ff60..6d0ad44d 100644
--- a/backtrace-library/src/main/java/backtraceio/library/services/BacktraceEventsHandler.java
+++ b/backtrace-library/src/main/java/backtraceio/library/services/BacktraceEventsHandler.java
@@ -10,7 +10,6 @@
 import backtraceio.library.common.BacktraceSerializeHelper;
 import backtraceio.library.interfaces.Api;
 import backtraceio.library.logger.BacktraceLogger;
-import backtraceio.library.models.json.BacktraceAttributes;
 import backtraceio.library.models.metrics.Event;
 import backtraceio.library.models.metrics.EventsPayload;
 import backtraceio.library.models.metrics.EventsResult;
@@ -52,22 +51,13 @@ abstract class BacktraceEventsHandler<T extends Event> extends Handler {
      */
     private int maximumNumberOfEvents = 350;
 
-    /**
-     * The application name
-     */
-    protected String application;
-
-    /**
-     * The application version
-     */
-    protected String appVersion;
-
     /**
      * Create BacktraceEventsHandler instance
-     * @param backtraceMetrics          Backtrace metrics object
-     * @param api                       Backtrace API object
-     * @param backtraceHandlerThread    Backtrace handler thread object
-     * @param urlPrefix                 Url routing prefix for metrics
+     *
+     * @param backtraceMetrics       Backtrace metrics object
+     * @param api                    Backtrace API object
+     * @param backtraceHandlerThread Backtrace handler thread object
+     * @param urlPrefix              Url routing prefix for metrics
      */
     public BacktraceEventsHandler(BacktraceMetrics backtraceMetrics,
                                   Api api,
@@ -89,11 +79,7 @@ public BacktraceEventsHandler(BacktraceMetrics backtraceMetrics,
         this.timeBetweenRetriesMillis = backtraceMetrics.settings.getTimeBetweenRetriesMillis();
 
         long timeIntervalMillis = backtraceMetrics.settings.getTimeIntervalMillis();
-
-        BacktraceAttributes backtraceAttributes = new BacktraceAttributes(backtraceMetrics.getContext(), null, null);
-        this.application = backtraceAttributes.getApplicationName();
-        this.appVersion = backtraceAttributes.getApplicationVersionOrEmpty();
-
+        
         if (timeIntervalMillis != 0) {
             final BacktraceEventsHandler handler = this;
             handler.postDelayed(new Runnable() {
diff --git a/backtrace-library/src/main/java/backtraceio/library/services/BacktraceMetrics.java b/backtrace-library/src/main/java/backtraceio/library/services/BacktraceMetrics.java
index 82dbf461..980c6f84 100644
--- a/backtrace-library/src/main/java/backtraceio/library/services/BacktraceMetrics.java
+++ b/backtrace-library/src/main/java/backtraceio/library/services/BacktraceMetrics.java
@@ -4,11 +4,11 @@
 
 import org.jetbrains.annotations.NotNull;
 
-import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ConcurrentLinkedDeque;
 
 import backtraceio.library.BacktraceCredentials;
+import backtraceio.library.common.ApplicationMetadataCache;
 import backtraceio.library.common.BacktraceStringHelper;
 import backtraceio.library.common.BacktraceTimeHelper;
 import backtraceio.library.common.serialization.DebugHelper;
@@ -19,6 +19,7 @@
 import backtraceio.library.logger.BacktraceLogger;
 import backtraceio.library.models.BacktraceMetricsSettings;
 import backtraceio.library.models.json.BacktraceAttributes;
+import backtraceio.library.models.attributes.ReportDataBuilder;
 import backtraceio.library.models.metrics.SummedEvent;
 import backtraceio.library.models.metrics.UniqueEvent;
 
@@ -117,6 +118,16 @@ public final class BacktraceMetrics implements Metrics {
      */
     private final BacktraceCredentials credentials;
 
+    /**
+     * Application name
+     */
+    private String applicationName;
+
+    /**
+     * Application version
+     */
+    private String applicationVersion;
+
     /**
      * Create new Backtrace metrics instance
      *
@@ -170,6 +181,11 @@ public void enable(BacktraceMetricsSettings settings, String uniqueEventName) {
         if (uniqueEventName == null || uniqueEventName.length() == 0) {
             throw new IllegalArgumentException("Unique event name must be defined!");
         }
+
+        ApplicationMetadataCache applicationMetadata = ApplicationMetadataCache.getInstance(this.getContext());
+        this.applicationName = applicationMetadata.getApplicationName();
+        this.applicationVersion = applicationMetadata.getApplicationVersion();
+        
         final long startMetricsSetup = DebugHelper.getCurrentTimeMillis();
 
         setStartupUniqueEventName(uniqueEventName);
@@ -186,6 +202,17 @@ public void enable(BacktraceMetricsSettings settings, String uniqueEventName) {
         BacktraceLogger.d(LOG_TAG, "Setup metrics integration took " + (endMetricsSetup - startMetricsSetup) + " milliseconds");
     }
 
+    /**
+     * Attributes are passed by the reference from the Backtrace client instance.
+     * If we modify them in the constructor, we won't be able to get "up to date"
+     * version from the client anymore.
+     * Due to that, we need to have a getter that will always transform attributes to a simple format.
+     */
+    private Map<String, String> getClientMetricsAttributes() {
+        return ReportDataBuilder.getReportAttributes(customReportAttributes, true).getAttributes();
+    }
+
+
     private void verifyIfMetricsAvailable() {
         if (!enabled) {
             throw new IllegalArgumentException("Metrics are not available!");
@@ -213,6 +240,7 @@ public void sendStartupEvent() {
         verifyIfMetricsAvailable();
         addUniqueEvent(startupUniqueEventName);
         addSummedEvent(startupSummedEventName);
+
         uniqueEventsHandler.send();
         summedEventsHandler.send();
     }
@@ -251,7 +279,9 @@ public boolean addUniqueEvent(String attributeName, Map<String, Object> attribut
             return false;
         }
 
-        Map<String, Object> localAttributes = createLocalAttributes(attributes);
+        Map<String, String> metricsAttributes = ReportDataBuilder.getReportAttributes(attributes, true).getAttributes();
+
+        Map<String, String> localAttributes = createLocalAttributes(metricsAttributes);
 
         // validate if unique event attribute is available and
         // prevent undefined attributes
@@ -304,7 +334,7 @@ public int count() {
     /**
      * Add a summed event to the next Backtrace Metrics request
      *
-     * @param metricGroupName
+     * @param metricGroupName name of the metrics group
      * @return true if success
      */
     public boolean addSummedEvent(String metricGroupName) {
@@ -314,8 +344,8 @@ public boolean addSummedEvent(String metricGroupName) {
     /**
      * Add a summed event to the next Backtrace Metrics request
      *
-     * @param metricGroupName
-     * @param attributes
+     * @param metricGroupName name of the metrics group
+     * @param attributes      metrics attributes
      * @return true if success
      */
     public boolean addSummedEvent(String metricGroupName, Map<String, Object> attributes) {
@@ -326,12 +356,10 @@ public boolean addSummedEvent(String metricGroupName, Map<String, Object> attrib
             return false;
         }
 
-        Map<String, Object> localAttributes = new HashMap<>();
-        if (attributes != null) {
-            localAttributes.putAll(attributes);
-        }
+        Map<String, String> metricsAttributes = ReportDataBuilder.getReportAttributes(attributes, true).getAttributes();
 
-        SummedEvent summedEvent = new SummedEvent(metricGroupName, BacktraceTimeHelper.getTimestampSeconds(), localAttributes);
+        SummedEvent summedEvent = new SummedEvent(metricGroupName);
+        summedEvent.addAttributes(metricsAttributes);
         summedEventsHandler.events.addLast(summedEvent);
         if (count() == maximumNumberOfEvents) {
             uniqueEventsHandler.send();
@@ -386,17 +414,25 @@ private boolean shouldProcessEvent(String name) {
         return true;
     }
 
-    protected Map<String, Object> createLocalAttributes(Map<String, Object> attributes) {
-        Map<String, Object> localAttributes = new HashMap<>();
+    protected Map<String, String> createLocalAttributes(Map<String, String> attributes) {
+        BacktraceAttributes backtraceAttributes = new BacktraceAttributes(context, null, null, true);
 
-        if (attributes != null) {
-            localAttributes.putAll(attributes);
+        Map<String, String> result = backtraceAttributes.attributes;
+        result.putAll(this.getClientMetricsAttributes());
+
+        if (attributes != null && !attributes.isEmpty()) {
+            result.putAll(attributes);
         }
 
-        BacktraceAttributes backtraceAttributes = new BacktraceAttributes(context, null, customReportAttributes);
-        localAttributes.putAll(backtraceAttributes.getAllAttributes());
+        return result;
+    }
+
+    protected String getApplicationName() {
+        return applicationName;
+    }
 
-        return localAttributes;
+    protected String getApplicationVersion() {
+        return applicationVersion;
     }
 
     /**
diff --git a/backtrace-library/src/main/java/backtraceio/library/services/SummedEventsHandler.java b/backtrace-library/src/main/java/backtraceio/library/services/SummedEventsHandler.java
index 14206828..85b27ade 100644
--- a/backtrace-library/src/main/java/backtraceio/library/services/SummedEventsHandler.java
+++ b/backtrace-library/src/main/java/backtraceio/library/services/SummedEventsHandler.java
@@ -1,5 +1,7 @@
 package backtraceio.library.services;
 
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Map;
 import java.util.concurrent.ConcurrentLinkedDeque;
 
@@ -21,18 +23,15 @@ public SummedEventsHandler(BacktraceMetrics backtraceMetrics,
 
     @Override
     protected SummedEventsPayload getEventsPayload() {
-        Map<String, Object> attributes = backtraceMetrics.createLocalAttributes(null);
-
-        ConcurrentLinkedDeque<SummedEvent> eventsCopy = new ConcurrentLinkedDeque<>();
-
-        for (SummedEvent event : events) {
+        Map<String, String> attributes = backtraceMetrics.createLocalAttributes(null);
+        for (SummedEvent event: events) {
             event.addAttributes(attributes);
-            eventsCopy.addLast(new SummedEvent((SummedEvent) event));
         }
+        SummedEventsPayload payload = new SummedEventsPayload(
+                new ConcurrentLinkedDeque<>(events),
+                backtraceMetrics.getApplicationName(),
+                backtraceMetrics.getApplicationVersion());
         events.clear();
-
-        SummedEventsPayload payload = new SummedEventsPayload(eventsCopy, application, appVersion);
-
         return payload;
     }
 
diff --git a/backtrace-library/src/main/java/backtraceio/library/services/UniqueEventsHandler.java b/backtrace-library/src/main/java/backtraceio/library/services/UniqueEventsHandler.java
index 96d12846..6b7199f7 100644
--- a/backtrace-library/src/main/java/backtraceio/library/services/UniqueEventsHandler.java
+++ b/backtrace-library/src/main/java/backtraceio/library/services/UniqueEventsHandler.java
@@ -22,14 +22,13 @@ public UniqueEventsHandler(BacktraceMetrics backtraceMetrics,
 
     @Override
     protected UniqueEventsPayload getEventsPayload() {
-        Map<String, Object> attributes = backtraceMetrics.createLocalAttributes(null);
+        Map<String, String> attributes = backtraceMetrics.createLocalAttributes(null);
 
         for (UniqueEvent event : events) {
             event.update(BacktraceTimeHelper.getTimestampSeconds(), attributes);
         }
 
-        UniqueEventsPayload payload = new UniqueEventsPayload(events, application, appVersion);
-        return payload;
+        return new UniqueEventsPayload(events, backtraceMetrics.getApplicationName(), backtraceMetrics.getApplicationVersion());
     }
 
     @Override
diff --git a/backtrace-library/src/test/java/backtraceio/library/ReportDataAnnotationBuilderTest.java b/backtrace-library/src/test/java/backtraceio/library/ReportDataAnnotationBuilderTest.java
new file mode 100644
index 00000000..a0259ee9
--- /dev/null
+++ b/backtrace-library/src/test/java/backtraceio/library/ReportDataAnnotationBuilderTest.java
@@ -0,0 +1,49 @@
+package backtraceio.library;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+
+import static org.junit.Assert.assertEquals;
+
+import backtraceio.library.models.attributes.ReportDataAttributes;
+import backtraceio.library.models.attributes.ReportDataBuilder;
+
+@RunWith(Parameterized.class)
+public class ReportDataAnnotationBuilderTest {
+
+    @Parameterized.Parameters
+    public static Collection<Object[]> data() {
+        return Arrays.asList(new Object[][]{
+                {new HashMap<String, String>() {{
+                    put("add", "value");
+                }}},
+                {new HashSet<String>() {{
+                    add("value");
+                }}},
+                {new Object()},
+        });
+    }
+
+    private final Object annotation;
+
+    public ReportDataAnnotationBuilderTest(Object annotation) {
+        this.annotation = annotation;
+    }
+
+    @Test
+    public void correctlySetComplexObjectAsAnnotation() {
+        String key = "annotation-key";
+        ReportDataAttributes data = ReportDataBuilder.getReportAttributes(new HashMap<String, Object>() {
+            {
+                put(key, annotation);
+            }
+        });
+        assertEquals(data.getAnnotations().get(key), annotation);
+    }
+}
diff --git a/backtrace-library/src/test/java/backtraceio/library/ReportDataAttributeBuilderTest.java b/backtrace-library/src/test/java/backtraceio/library/ReportDataAttributeBuilderTest.java
new file mode 100644
index 00000000..dd0cd75d
--- /dev/null
+++ b/backtrace-library/src/test/java/backtraceio/library/ReportDataAttributeBuilderTest.java
@@ -0,0 +1,67 @@
+package backtraceio.library;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashMap;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import backtraceio.library.models.attributes.ReportDataAttributes;
+import backtraceio.library.models.attributes.ReportDataBuilder;
+
+@RunWith(Parameterized.class)
+public class ReportDataAttributeBuilderTest {
+
+    private final String key = "attribute-key";
+
+    @Parameterized.Parameters
+    public static Collection<Object[]> data() {
+        return Arrays.asList(new Object[][]{
+                {"String value"},
+                {123},
+                {45.67},
+                {true},
+        });
+    }
+
+    private final Object primitiveValue;
+
+    public ReportDataAttributeBuilderTest(Object primitiveValue) {
+        this.primitiveValue = primitiveValue;
+    }
+
+    @Test
+    public void correctlySetPrimitiveValueIntoAttribute() {
+        ReportDataAttributes data = ReportDataBuilder.getReportAttributes(new HashMap<String, Object>() {
+            {
+                put(key, primitiveValue);
+            }
+        });
+        assertEquals(data.getAttributes().get(key), primitiveValue.toString());
+    }
+
+    @Test
+    public void shouldSetNullableValueAsAttribute() {
+        ReportDataAttributes data = ReportDataBuilder.getReportAttributes(new HashMap<String, Object>() {
+            {
+                put(key, null);
+            }
+        });
+        assertNull(data.getAttributes().get(key));
+    }
+
+    @Test
+    public void shouldSkipNullableValue() {
+        ReportDataAttributes data = ReportDataBuilder.getReportAttributes(new HashMap<String, Object>() {
+            {
+                put(key, null);
+            }
+        }, true);
+        assertNull(data.getAttributes().get(key));
+    }
+}
diff --git a/example-app/src/main/java/backtraceio/backtraceio/MainActivity.java b/example-app/src/main/java/backtraceio/backtraceio/MainActivity.java
index f0c3f1cb..e0f5be57 100644
--- a/example-app/src/main/java/backtraceio/backtraceio/MainActivity.java
+++ b/example-app/src/main/java/backtraceio/backtraceio/MainActivity.java
@@ -51,7 +51,7 @@ public void setOnServerResponseEventListener(OnServerResponseEventListener e) {
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        
+
         backtraceClient = initializeBacktrace(BuildConfig.BACKTRACE_SUBMISSION_URL);
 
         symlinkAndWriteFile();