Your game progress on Android OS devices is saved by logging into your Google Play account. In order to connect your profile to a Google Play account, please complete the following steps:

1) Open the game and go to the in-game settings screen (the gear icon in the top left corner of the screen);

2) Press the "Connect" button and select the Google Play account in the pop-up window to which you would like to connect the game.

By connecting your profile to the Google Play account you will secure your game progress in case of a reboot, factory reset, and will also allow you to play the game on multiple Android OS devices using your profile.

Note: you can only connect a single game profile to each Google Play account. Switching Google Play accounts will result in losing your game progress.