Please attempt the following to potentially resolve the issue:
Restart Your Device
Memory leaks can cause Charm King to freeze/crash. One way to potentially fix this is to restart your device. This clears your device's memory (don’t worry, your game data will not be lost).
Reset the Game
Another way to fix freezes is to reset your game. Go ahead! Try it out!
Update to the Latest Version of Charm King
You may be playing on an older version of the game. Visit the app store and look for updates to the game. Older versions of the game can result in performance issues, so it's always a good rule of thumb to keep the game updated to the latest version.
Update your Device
You should always make sure that your device is up to date with the latest software version.