I find if you load the maps, you can screen shot them and if the maps are already loaded and tracking the GPS in your phone can usually follow your position even without enough cell service to load the map. So basically what I'm saying is, if you get the area you are planning on fishing loaded while you still have service, and the app does not crash, you should be able to use the app as the GPS tracks. Honestly I usually just use mapquest for this purpose, since the older version of the app has all the stream names. I just identify the stream ahead of time then go by name on there. I, like pcray, use my computer when home. When I have found this app to be handy is when I am on the road and need a list of streams near by that support trout, especially when I am in an unfamiliar area. For instance, I took a friend to spring earlier this year, we fished all morning and caught quite a few fish, but wanted to move on to something else. Moved towards fishing creek but conditions were not good and temps were borderline for me, so I suggested we find a brookie stream to hit up for an hour or two. Pulled the app out, found the three closest streams with wild trout and drove around til we found one that looked good to fish. Would have had no idea where to look without this app, because we live 2 hours away from where we ended up. So no, I don't use this app a ton, but it's a nice resource and reference to use at times also.
Honestly my biggest issue is I forget what the colors of streams mean, and they don't all have the pins. I also find some inaccuracies, but that is no big deal. I would also like to be able to show multiple layers at once, if that makes sense. So for class a, wild repro, and wilderness streams all at once, etc, and leave all the stocked waters, warm water etc out.
That said, thanks for the app, better than nothing, and I'm sure with improvements it will only keep getting better.