diff --git a/changelog/unreleased/lang-supp-in-app.md b/changelog/unreleased/lang-supp-in-app.md
new file mode 100644
index 00000000000..042920589d4
--- /dev/null
+++ b/changelog/unreleased/lang-supp-in-app.md
@@ -0,0 +1,5 @@
+Enhancement: added support for language locales in apps
+
+This is a backport of code in the edge branch
+
+https://github.com/cs3org/reva/pull/3303
diff --git a/internal/grpc/services/appprovider/appprovider.go b/internal/grpc/services/appprovider/appprovider.go
index eea33b20c17..df979ebf746 100644
--- a/internal/grpc/services/appprovider/appprovider.go
+++ b/internal/grpc/services/appprovider/appprovider.go
@@ -170,7 +170,8 @@ func getProvider(c *config) (app.Provider, error) {
 }
 
 func (s *service) OpenInApp(ctx context.Context, req *providerpb.OpenInAppRequest) (*providerpb.OpenInAppResponse, error) {
-	appURL, err := s.provider.GetAppURL(ctx, req.ResourceInfo, req.ViewMode, req.AccessToken)
+	// TODO(lopresti) adding now an hardcoded language, in the HTTP appprovider in edge this is read as a form parameter from the frontend
+	appURL, err := s.provider.GetAppURL(ctx, req.ResourceInfo, req.ViewMode, req.AccessToken, "en-GB")
 	if err != nil {
 		res := &providerpb.OpenInAppResponse{
 			Status: status.NewInternal(ctx, errors.New("appprovider: error calling GetAppURL"), err.Error()),
diff --git a/pkg/app/app.go b/pkg/app/app.go
index a6edad2a022..50e6ce28d8b 100644
--- a/pkg/app/app.go
+++ b/pkg/app/app.go
@@ -40,6 +40,6 @@ type Registry interface {
 // Provider is the interface that application providers implement
 // for interacting with external apps that serve the requested resource.
 type Provider interface {
-	GetAppURL(ctx context.Context, resource *provider.ResourceInfo, viewMode appprovider.OpenInAppRequest_ViewMode, token string) (*appprovider.OpenInAppURL, error)
+	GetAppURL(ctx context.Context, resource *provider.ResourceInfo, viewMode appprovider.OpenInAppRequest_ViewMode, token, language string) (*appprovider.OpenInAppURL, error)
 	GetAppProviderInfo(ctx context.Context) (*registry.ProviderInfo, error)
 }
diff --git a/pkg/app/provider/demo/demo.go b/pkg/app/provider/demo/demo.go
index 896893fa658..9376251aa18 100644
--- a/pkg/app/provider/demo/demo.go
+++ b/pkg/app/provider/demo/demo.go
@@ -38,8 +38,8 @@ type demoProvider struct {
 	iframeUIProvider string
 }
 
-func (p *demoProvider) GetAppURL(ctx context.Context, resource *provider.ResourceInfo, viewMode appprovider.OpenInAppRequest_ViewMode, token string) (*appprovider.OpenInAppURL, error) {
-	url := fmt.Sprintf("<iframe src=%s/open/%s?view-mode=%s&access-token=%s />", p.iframeUIProvider, resource.Id.StorageId+":"+resource.Id.OpaqueId, viewMode.String(), token)
+func (p *demoProvider) GetAppURL(ctx context.Context, resource *provider.ResourceInfo, viewMode appprovider.OpenInAppRequest_ViewMode, token, language string) (*appprovider.OpenInAppURL, error) {
+	url := fmt.Sprintf("<iframe src=%s/open/%s?view-mode=%s&access-token=%s&lang=%s />", p.iframeUIProvider, resource.Id.StorageId+":"+resource.Id.OpaqueId, viewMode.String(), token, language)
 	return &appprovider.OpenInAppURL{
 		AppUrl: url,
 		Method: "GET",
diff --git a/pkg/app/provider/wopi/wopi.go b/pkg/app/provider/wopi/wopi.go
index bec75f63a39..88e2e03527c 100644
--- a/pkg/app/provider/wopi/wopi.go
+++ b/pkg/app/provider/wopi/wopi.go
@@ -125,7 +125,7 @@ func New(m map[string]interface{}) (app.Provider, error) {
 	}, nil
 }
 
-func (p *wopiProvider) GetAppURL(ctx context.Context, resource *provider.ResourceInfo, viewMode appprovider.OpenInAppRequest_ViewMode, token string) (*appprovider.OpenInAppURL, error) {
+func (p *wopiProvider) GetAppURL(ctx context.Context, resource *provider.ResourceInfo, viewMode appprovider.OpenInAppRequest_ViewMode, token, language string) (*appprovider.OpenInAppURL, error) {
 	log := appctx.GetLogger(ctx)
 
 	ext := path.Ext(resource.Path)
@@ -238,6 +238,19 @@ func (p *wopiProvider) GetAppURL(ctx context.Context, resource *provider.Resourc
 
 	appFullURL := result["app-url"].(string)
 
+	if language != "" {
+		url, err := url.Parse(appFullURL)
+		if err != nil {
+			return nil, err
+		}
+		urlQuery := url.Query()
+		urlQuery.Set("ui", language)      // OnlyOffice
+		urlQuery.Set("lang", language)    // Collabora
+		urlQuery.Set("UI_LLCC", language) // Office365
+		url.RawQuery = urlQuery.Encode()
+		appFullURL = url.String()
+	}
+
 	// Depending on whether wopi server returned any form parameters or not,
 	// we decide whether the request method is POST or GET
 	var formParams map[string]string
diff --git a/pkg/utils/utils.go b/pkg/utils/utils.go
index 14ec95e4faf..d78af3fec0b 100644
--- a/pkg/utils/utils.go
+++ b/pkg/utils/utils.go
@@ -24,6 +24,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"os"
 	"os/user"
 	"path"
 	"path/filepath"
@@ -348,7 +349,80 @@ func GetViewMode(viewMode string) gateway.OpenInAppRequest_ViewMode {
 		return gateway.OpenInAppRequest_VIEW_MODE_READ_ONLY
 	case "write":
 		return gateway.OpenInAppRequest_VIEW_MODE_READ_WRITE
+	case "preview":
+		return gateway.OpenInAppRequest_VIEW_MODE_PREVIEW
 	default:
 		return gateway.OpenInAppRequest_VIEW_MODE_INVALID
 	}
 }
+
+// AppendPlainToOpaque adds a new key value pair as a plain string on the given opaque and returns it
+func AppendPlainToOpaque(o *types.Opaque, key, value string) *types.Opaque {
+	o = ensureOpaque(o)
+
+	o.Map[key] = &types.OpaqueEntry{
+		Decoder: "plain",
+		Value:   []byte(value),
+	}
+	return o
+}
+
+// ReadPlainFromOpaque reads a plain string from the given opaque map
+func ReadPlainFromOpaque(o *types.Opaque, key string) string {
+	if o.GetMap() == nil {
+		return ""
+	}
+	if e, ok := o.Map[key]; ok && e.Decoder == "plain" {
+		return string(e.Value)
+	}
+	return ""
+}
+
+// ExistsInOpaque returns true if the key exists in the opaque (ignoring the value)
+func ExistsInOpaque(o *types.Opaque, key string) bool {
+	if o.GetMap() == nil {
+		return false
+	}
+
+	_, ok := o.Map[key]
+	return ok
+}
+
+// MergeOpaques will merge the opaques. If a key exists in both opaques
+// the values from the first opaque will be taken
+func MergeOpaques(o *types.Opaque, p *types.Opaque) *types.Opaque {
+	p = ensureOpaque(p)
+	for k, v := range o.GetMap() {
+		p.Map[k] = v
+	}
+	return p
+}
+
+// ensures the opaque is initialized
+func ensureOpaque(o *types.Opaque) *types.Opaque {
+	if o == nil {
+		o = &types.Opaque{}
+	}
+	if o.Map == nil {
+		o.Map = map[string]*types.OpaqueEntry{}
+	}
+	return o
+}
+
+// RemoveItem removes the given item, its children and all empty parent folders
+func RemoveItem(path string) error {
+	if err := os.RemoveAll(path); err != nil {
+		return err
+	}
+
+	for {
+		path = filepath.Dir(path)
+		if err := os.Remove(path); err != nil {
+			// remove will fail when the dir is not empty.
+			// We can exit in that case
+			return nil
+		}
+
+	}
+
+}