Locus Pro is really powerful for tracking and navigating but weak on its choice of topo base layers and not real user friendly. Backcountry Navigator is really powerful in terms of your choice of topo base layers, even having the most up to date Forest Service maps. The problem with with Backcountry Pro I think is they try to nickle and dime you to death when adding GMU's or landownership. Another cool free app is the PDF Maps in which you can download a lot of free USGS topos, they have a bunch of maps to buy to but they are pretty cheap. I use Locus Pro and PDF Maps both. With PDF Maps Its real easy to upload your points and tracks to google earth or make points in google earth and download to your phone. For my phone I bought a 20 dollar charger that takes AA batteries and had no problems running out of juice on 3 and 4 day backcountry trips.
