BodyFast is available in German, English, Spanish, French, Italian and Portuguese. In order to change the language in the  app you have to change the language settings on your device. The language in the app then will adapt automatically. 

Apple / iOS:

You can cancel your subscription directly in the Apple system by using the following link:

https://apple.co/2Th4vqI

If  this does not work as expected you may also contact the Apple customer  care department for more information as to your account status and to  cancel your subscription: https://support.apple.com/contact or by calling their support number in your region.

Android phones / tablets:

Please use the following cancellation link for Android phones:
http://play.google.com/store/account/subscriptions

I hope this helps you!