You can ise your Sdui app to different languages.
The app is currently available in the following languages: 

German, English, Spanish, Turkish
More languages will follow shortly.

In the app, click on the menu in the top right corner and then on "Account & Settings".
Open your profile and click on the point "Language" and select the desired language. Then click on "Save" after.

Note: This function is currently only used to translate the Sdui app, not its content such as chat messages.