OsmAnd+ !!
https://f-droid.org/en/packages/net.osmand.plus
This is the full "paid" version that grants unlimited map/resource downloads, though you can just grab those outside the app anyway: https://download.osmand.net/list.php
I use OSMAnd daily in Montreal, and do OSM edits with it often enough. I've used it across Europe and Japan with great successes, for walking, driving, hiking, biking, and yes even downhill skiing.
It is also ESPECIALLY useful and way more powerful for biking and hiking that Google Maps in my opinion, map data is far more fine grained and there's so much control over routing + other such features.
Also WAY more POI visibility with OSMAnd/OSM, like ability to find very specific/generic POIs you may be looking for (ex. Restroom, all grocery stores in area, nearby green space), rather than just what may have been put into Google Maps et al.
I guess one other downside is potential lack of up to date info; that's more on OSM though.
Only major downside is public transit routing in some cases, Google Maps is still best for that unfortunately, and I do turn to Maps for that often... OSMAnd I don't feel will ever match corporate maps for public transit, especially in cities with trains+metro+tram+bus+etc.
Have fun!!!!!
