Since I hunt exclusively WMA and some TVA land, boundaries are super important to me. I use BackCountry Navigator Pro. The thing I like is I am able to import map files that I export from Google MyMaps. Using county GIS maps, the DCNR interactive map and TVA's online maps, I have been able to create very accurate boundary data for Skyline and other areas in northern Alabama. BackCountry Navigator also had many options for backgrounds such as satellite and topo maps, but generally I prefer the Google maps imagery which you can download to the phone and not have to rely on cell coverage. Recording your track and marking waypoints like scrapes, rubs and stand locations is easy. BCN is Android only, but I have heard that Gaia GPS I'd very good but a little pricey.