How to change the language of Polar Flow and Polar Beat
Here's how to change the app language on both mobile platforms:
The app language is the same language that your phone operating system uses. The only way to change the app language is to change the phone language in the phone settings.
You can also change the app language separately from the phone language from iOS 13 onwards. On iPhone, go to Settings > Polar Flow / Polar Beat > Language and choose the one you want.