Funded by the US National Science Foundation, implemented at the University of Minnesota, the "Flyover Country" mobile app is a very useful, unique and free app for Android and iOS, which enriches the exploration experience using offline maps whether you're flying, travelling by car, or trekking through nature's wonders. It is voted one of the best science apps available today by Popular Mechanic.
AGPS-TrackerOm is an interesting and quite a robust Android application. It's main function is to follow preloaded tracks and record your tracks, and tries to do so reliably - ensuring that the GPS data is recorded at all times, even when the phone goes into stand-by mode. This means you won't get surprise straight lines in your GPX tracks. It can also provide enhanced accuracy of your current elevation, by using altitudes from NASA-generated Digital Elevation Models (DEMs).
AGPS-TrackerOm (previously called A-GPS Tracker++), differs from the lighter version, A-GPS Tracker in the following:
- AGPS-TrackerOm uses offline maps maintained by OpenStreetMap, which you need to preload. The "lighter" A-GPS Tracker uses Google maps which are not available offline.
- You can download Digital Elevation Models (DEM) which allow the app to display altitude contour lines and provide DEM altitude along with GPS altitude, the former being more accurate
