I've become a fan of MAPS.ME with its offline maps on my ride across the Americas.

I don't use it for continuous navigation. I also don't necessarily always have a cell coverage (either SIM card or when I have one cell coverage). However, what I find helpful is turning on the phone, firing up MAPS.ME and get a quick confirmation of where I am located and the likely road choices.

I will have put in my likely destinations as bookmarks the night or two before when I had more time to sort things out with an internet connection as well as a rough guide on my route. Outside of the big cities, the routing is often straightforward as in "follow the highway to X". However, inside the towns there is sometimes ambiguity like "what exit on the roundabout leads to the highway" and here is where MAPS.ME is very helpful.