Having spent a very limited amount of time hunting western states I can't really comment on the usefulness of this app. The first thing that comes to my mind though is that any place I would hunt is not real likely to have top notch cell service. Oops, I dropped my phone and shattered the screen. Oops, I forgot to charge my phone. Now I'm out here in the middle of F'ing nowhere and I don't have a clue how I got here, how to get back out and I don't have a map or a compass.
Maybe it's just me, the old man. Get off my lawn.