Sorry to bother you here, but I thought I was a little Off Topic in the discussion.
If you're having issues with the app (i'm on iOS, but may work for Android), just delete the app and re-install it. That fixed the issues of having to log in repeatedly, and there were some Rock Central Server issues in the previous season, so that may have also affected the app.
I tried many times, I also cleaned the cache, but it didn't work... If they'll do an update for the app maybe it will run again... we'll see.0July 15
The app stopped working for me during Season 6 when they had Server issues. But, after deleting it and re-downloading it, it seemed to start working again.
It probably needs an update (like the game does)... bugs galore at the moment!