Recs.
Updated
Specs
Pros
Cons
Con Maps can't be stored on SD card
The maps take up several GB of space, and cannot be stored on SD, so it is easily the largest app on the phone and is frustrating to deal with. Only with a rooted phone can you use Apps2SD or the like to store the maps on SD and free up internal storage space.
Con Map search is awful
Searching for map files is very frustrating as the map search only shows the center point of each map as a pin, so you can't see whether the map includes a point you're interested in, and since there are usually many historical maps of the same location, they produce many pins appearing on top of each other. You have to download each one and open it in order to see what it will look like, rather than previewing them in the live display. Good overview maps will appear as pins in random locations, while there will be tons of topo map tiles everywhere else
Recommendations
Comments
Out of Date Pros + Cons
Con Only shows one map at a time
It supports USGS topo maps, for instance, but if you walk off the edge of one, you have to manually load the adjacent map, which is a hassle. It would be nice if, like other apps, you could select "USGS topo" as the map source, and it would automatically show whichever specific map your location is currently near the middle of (since the USGS maps have margins and legends, etc.)