It's always a good idea to connect your game to Facebook to save your
progress and make it easier to switch to another device or uninstall
and reinstall the game on the same device. However, if you want to have
multiple games, be careful with Facebook connect.
To connect to Facebook, go to the settings menu and tap "Connect" with the Facebook icon. Be sure you are logged in to the Facebook account you wish to use. Now you can recall your game from any device and even if you have to reinstall the game someday.
