If your game is freezing or running slowly, your device may be low on available memory (RAM) or storage space. Restart your device and ensure that you close all other apps to prevent the game from freezing due to lack of memory.
We recommend that you have at least 2GB of free space on your device. If your phone doesn't have enough RAM, it may have trouble running the game. As of this time, the best way to fix these issues is to restart your device, which clears the memory (this will not cause any loss of data).