When the tutorial has been completed, you will be asked if you would like to connect to Facebook. You can either connect now, or hit the X at the top of the message prompt. If you decide later that you would like to merge your Guest game with Facebook, you can do so from the in game options menu (the gear symbol). When you select the “Connect” button, you will be asked if you would like to “merge” your game with Facebook or “never”. If you select “never”, a fresh game will be started on Facebook and your Guest game will remain separate. If you want to enter your separate Guest game again, simply hit the LOG OUT button and select "Guest".
If you select “merge” your Guest data will be linked to your Facebook account and is now saved on the server. You can now connect through any compatible device. Just select the Facebook option when you launch the game.