BIG ERROR FIX THREAD:
If App Crashes on Start up:
Enable Permissions for Storage & Phone
If App is in a White screen:
Clear Cache and force stop the app.
If App is detected as Unauthorized or modified:
Force Close the game!
Clear Cache, Force stop and if it's still not working unallow all permissions and reallow.
If app isn't downloading:
Make sure to install
SIGNED: If you don't have rooted device. If you don't know what root is you probably don't have root so install this one.
UNSIGNED: If you have root + LuckPatch Patchers installed.
If you don't know if you have root or not, most likely you don't have root.