"Maps" is the Maps.me app but without the adverts and tracking.

For the record OpenStreetMap doesn't have one official app. It doesn't even have any "official" apps. People use OSM data to make other maps.

I've been using OSMAnd+ for a while now and it's awesome. Offline maps, navigation with voice prompts, pretty much everything you expect, and it doesn't spam your location to a third party. Yay!

It's also available in the play store for $8.99. I just bought it to give it a try. Thanks for introducing it to me!