This is the best. You can download any geo referenced map, and use your phones GPS to show your location on the map. They have maps you can download, or use your local OHV areas website, forest service, etc.
Backcountry navigator work good. Has a few different topo maps and couple different aerial maps. Can download the map where you ride and use while your offline.
Myself & @Hondasxs have been using ORUX map app al the typical map files that work on a Garmin GPS import right into it giving you instant access to tens of thousands of miles of trail maps.