What's the best apps as a Google maps replacement that uses open street maps?
But yes, the development force remains mostly French for now. Waiting for more European contributions...
On other fronts, like hiking trails or public infrastructure, you'll find OSM much more accurate, especially around the world (I hear that Google is comparatively good on their home market). If you want things like trip planning, nautical maps, road avoidance, and tons more features: OsmAnd can do basically everything but the sheer feature count also clutters the UI. I have no problem with it but others say they prefer CoMaps and other apps for the simpler tasks, so just be aware of the different pros/cons and enjoy :)