Originally Posted by
JeffH Nav4All and amAze are free alternatives that may be worth your time to consider. Apps generally can't be run from a Media card. TrekBuddy is one GPS/Mapping app that lets you download maps in advance and store them on a Media Card, for use in areas where you don't have cell coverage. TrekBuddy has to run in device memory, but it uses the card for its maps. All the other mapping apps download their maps in real time, cache them in device memory, and delete the old ones to make room for newer ones, so they don't completely fill up your memory.