Apparently they plan to add support for it this year: https://www.db.com/news/detail/20241122-european-digital-payments-app-wero-now-available-for-postbank-customers?language_id=3

I've been using FitoTrack recently: https://codeberg.org/jannis/FitoTrack

Available on the AppStore and F-Droid

Tracking and logging/history and statistics works flawlessly for me so far, the rest of the app is quite minimalistic, but I like that, not every app needs to be a bloated social media network imho

Don't think there's any self hosting possible or rather necessary since it's all locally anyway as far as I see but it has an option for exporting the data and creating automatic backups