Use your phone or tablet as an offroad topo mapping GPS with the bestselling outdoor navigation app for Android! Explore beyond cell coverage for hiking, hunting and more.

Download topo maps for the US and some other countries in advance, so you won't need cell coverage when navigating.

This uses many publicly available map sources as free downloads. It also has some additional content available as an in app purchase:
Boundary maps for 12 western states from the Bureau of Land Management(BLM) for $7.99. Great for hunters, hikers, and prospectors.
Content from US TrailMaps for $15.99, including:
Snowmobile Trail Maps for Snowmobiling enthusiasts,
ATV Trail Maps
Whitewater Trail Maps,
Equestrian Trail maps.
See these in the menu under More-> "Purchasing AddOns".

You are welcome to try the DEMO version to make sure you like the maps in your country.

NOTE: If you've already purchased this or any paid app, you can install it at any time from 'My Apps' in the Android Market.

Use offline topo maps and GPS on hiking trails without cell service! The GPS in your Android phone can get its position from GPS satellites, and you don’t have to rely on your data plan to get maps. Have more fun and safe GPS adventures in the backcountry.

Preload offline topo maps, aerial photos, and road maps on your storage card, so they are ready when you need them for your GPS navigation. Many free map source are built into the app.

Add custom GPS waypoints in longitude and latitude, UTM or MGRS grid reference. Import GPS waypoints from GPX files. Choose mapsource-like icons for GPS waypoints. (This app uses the WGS84 datum, NAD27 is available in settings).

Use GPS for hunting a waypoint or geocache, for recording tracks and GPS waypoints on your trip, all the while tracking your GPS quest on topographic maps.

What's in this version : (Updated : Oct 29, 2015)
Resolving incomplete text labels.
Better rendering performance.
Elevation estimate upgrades
better server performance at geonames
resolve failure to create route
Addons include Accuterra map source, GMUs of various states. SnowMobile trail maps, ATV, Equestrian, Birding, and Whitewater trail maps, and BLM Land Boundary Maps of 12 western states.
Required Android O/S : 1.6+