Organic Maps is the OSS fork of Maps.me, which was basically the best maps app ever made, but was sold. Both use OSM but also can load other map sources (iirc). I used to use Maps.me extensively when traveling abroad as it provided way better maps than Google, and all offline.
This is a tried and tested platform that works great, led by people who know their stuff and care deeply about the user. Please donate if you like it: https://github.com/organicmaps/organicmaps
This is a tried and tested platform that works great, led by people who know their stuff and care deeply about the user. Please donate if you like it: https://github.com/organicmaps/organicmaps