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 or Google accounts to make sure your progress is saved. That's how you do it:
- Go to Settings and tap on Save Progress.
- Choose the preferred option and log into your account.
You can pick multiple options at once to save your progress and disconnect any of the linked accounts anytime in your game settings.
NOTE: if you do a factory reset or break/lose your device, you can only restore your progress if your game was previously connected to one of the aforementioned services. If you didn't link your game to Facebook or Google, there's a high risk of losing your achievements irretrievably.