Hiking App

The tour app of “Gastlandschaften Rheinland-Pfalz” from Outdooractive is available free of charge in the Apple Store and on Google play.
The tour planner contains cycling routes and hiking trails.

It even works offline, but the app only exists in German.

https://apps.apple.com/de/app/touren-in-rheinland-pfalz/id449845449

https://play.google.com/store/apps/details?id=de.alpstein.alpregio.Rlp&feature=search_result