On Android version of the app, Simple is available in English, Spanish, French, German, Portuguese (Brazil), Italian, Swedish, Turkish, Norwegian, Polish, Dutch, Danish, and Latin American Spanish.
How to choose your preferred language in your phone settings:
Go to the Profile section by tapping the profile icon in the upper-right corner (it may appear on the Home, Track, or My Plan tab in different app versions)
On the next screen, tap on Language:
Choose the preferred language:
After that, your app should restart and open with the new language settings.