diff --git a/greeting/android/build.gradle b/greeting/android/build.gradle
index 8f38257..cfe8992 100644
--- a/greeting/android/build.gradle
+++ b/greeting/android/build.gradle
@@ -12,4 +12,6 @@ dependencies {
 
     // Specify dependency on a common project for Kotlin multiplatform build.
     expectedBy project(':greeting:common')
+
+    testImplementation "org.jetbrains.kotlin:kotlin-test-junit:$kotlin_version"
 }
diff --git a/greeting/android/src/test/kotlin/CalculatorTestJavaHelper.kt b/greeting/android/src/test/kotlin/CalculatorTestJavaHelper.kt
new file mode 100644
index 0000000..3ec214c
--- /dev/null
+++ b/greeting/android/src/test/kotlin/CalculatorTestJavaHelper.kt
@@ -0,0 +1,8 @@
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import kotlin.test.Ignore
+
+// special class for running test within IDE
+@Ignore
+@RunWith(JUnit4::class)
+class CalculatorTestJavaHelper : CalculatorTest()
diff --git a/greeting/common/build.gradle b/greeting/common/build.gradle
index f3ed1c6..35c85d8 100644
--- a/greeting/common/build.gradle
+++ b/greeting/common/build.gradle
@@ -9,4 +9,7 @@ version = 1.0
 dependencies {
     // Set up compilation dependency on common Kotlin stdlib
     implementation "org.jetbrains.kotlin:kotlin-stdlib-common:$kotlin_version"
+
+    testImplementation "org.jetbrains.kotlin:kotlin-test-common:$kotlin_version"
+    testImplementation "org.jetbrains.kotlin:kotlin-test-annotations-common:$kotlin_version"
 }
diff --git a/greeting/common/src/main/kotlin/Calculator.kt b/greeting/common/src/main/kotlin/Calculator.kt
new file mode 100644
index 0000000..f74530b
--- /dev/null
+++ b/greeting/common/src/main/kotlin/Calculator.kt
@@ -0,0 +1,5 @@
+class Calculator {
+    companion object {
+        fun sum(a: Int, b: Int): Int = a + b
+    }
+}
\ No newline at end of file
diff --git a/greeting/common/src/test/kotlin/CalculatorTest.kt b/greeting/common/src/test/kotlin/CalculatorTest.kt
new file mode 100644
index 0000000..92584c9
--- /dev/null
+++ b/greeting/common/src/test/kotlin/CalculatorTest.kt
@@ -0,0 +1,10 @@
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+open class CalculatorTest {
+
+    @Test
+    fun testSum() {
+        assertEquals(3, Calculator.sum(1, 2))
+    }
+}
diff --git a/greeting/ios/build.gradle b/greeting/ios/build.gradle
index a90f29b..a1a6472 100644
--- a/greeting/ios/build.gradle
+++ b/greeting/ios/build.gradle
@@ -9,6 +9,24 @@ konanArtifacts {
         // The multiplatform support is disabled by default.
         enableMultiplatform true
     }
+
+    library('NativeLib') {
+        enableMultiplatform true
+    }
+
+    program('NativeTest') {
+        srcDir 'src/test/kotlin'
+        commonSourceSet 'test'
+        libraries {
+            artifact 'NativeLib'
+        }
+        extraOpts '-tr'
+    }
+}
+
+task test(dependsOn: 'compileKonanNativeTestIos_x64', type: Exec) {
+    def textExecutable = tasks["compileKonanNativeTestIos_x64"].artifactPath
+    commandLine("xcrun", "simctl", "spawn", "iPhone 8", textExecutable)
 }
 
 dependencies {