I use this routinely, and as I am on Open Street Map editor, I have added hundreds of way points to areas I ususally visit
Pros:No need for cell, uses Open Street Maps, point to point navigation
Cons:Relies on open street map, which you can edit, but if the POI doesn't exis in OSM, you can't navigate to it
I use Maps.me to follow routes by bicycle that I create in Strava's route builder. Have crossed the US and used it throughout Europe. Great that I can add info to places I find along the way. Run it in airplane mode to get the most from your battery life and navigate through areas without data coverage.
Tried some other options but always come back to this.
Pros:Free
Easy
Detailed
Simple
Cons:Route to can be a bit slow in offline mode
Often Prompts to use data when in offline mode
Mysuper.fan