I did the GAP in Sept. last year. In Confluence, I didn't have a reservation at the campground, and none of the rangers could figure out how to do it on my phone. I asked a lady in a Winnebago and she said the app made it easier. My phone would not install the app without my Apple password which I had carefully written down on a piece off paper, in my desk at home. Fortunately I was able to tell the Rangers the story of how a particular NP, that they had all worked at, came into existence. They let me stay.
I ate at a nice restaurant/inn on the river bank.