This is a well thought-out app with intuitive interface and lots of options. Fills a much-needed niche of on-board topo maps - which are downloaded for free from NRCan (for Canada) via a simple tile interface or via Search, which seems to be pretty comprehensive. Touch-and-hold controls are a nice touch (not intuitive - but help manual is very complete).
Now - with a basic topo viewer, the next step is to provide an ability to save waypoints, record a trek (start, pause, save), share a trek (out to GoogleMaps/Earth via kml), view elevation profile of a trek, measure distances, etc etc.. (this is where the 5th star would come from).
Great start with new features to follow hopefully! Defintely worth the modest price - Check this app out - Drew
Drew Shantz about Topo Maps