You can connect Angry Birds Blast to Facebook on the starting screen after opening the game. Just tap the blue “Login” button. You can also log in from the settings menu. Tap the menu button in the bottom left of the level map screen, tap the cogwheel, and tap the blue “Login” button. If you want to disconnect the game from Facebook, you can also do that in the settings menu.
Connecting the game to Facebook saves your game progress to the cloud, allowing you to pick up where you left off on another device or after uninstalling/reinstalling the game. We highly recommend doing this to keep your progress secured.