Closing app with the 'X' doesn't work. App stays running in the background and will re-open multiple occurrences of the program if you relaunch it and eventually it will crash. Help guide is also lacking. I'll be uninstalling this one for sure.
Step 1: Restart & update
Restart your phone
Check for Android updates
Update the app
Step 2: Check for a larger app issue
Force stop the app
Clear the app's cache & data
Sync device with Google servers
Uninstall the app
Contact the app developer