Your game progress is saved automatically if your device is connected to the internet, so it won't be lost even if you reinstall the game.

You can also connect your game to Facebook to save your progress. You don't need to do anything besides connect it.

IMPORTANT NOTE: if you reset all the settings on your device, you can only restore your progress on your own if the game is connected to Facebook. You can also only transfer progress from one device to another when the game is connected to Facebook.