Just to clarify, OSM is the acronym for Open Street Map, which is just the map/database
OsmAND, comaps, and organicmaps are all apps/clients that use OSM as their source of map data, and add gps navigation functionality
Comaps was forked recently cause there were some issues with organic maps being run in kind of a crummy way that wasn't in line with the community, if I understand right. But I'm sure someone more knowledgeable could elaborate better
I dunno if this clarification was needed or helpful but I figured I'd add it in case it's of help :)
I like the organic maps UI, and I have liked the OsmAND functionality, but I'm still working on transitioning away from google maps so I have limited perspective. I do know there's an app that wraps the google maps website so you can use it without google servicesor whatever and potentially less risk of tracking, and that may be of use depending on your needs!