1. Please make sure that you have the latest iOS version. Navigate to Settings > General > Software and check if an update is available.

2. Make sure your device has enough free space. Navigate to Settings > About and check "Capacity" and "Available." You can free space by removing unnecessary apps.

3. Close all the apps that are running in the background. Double tap "Home" button to see all the apps which are currently running and swipe upwards to close them. As an alternative, you can try reloading the device (turn it off and on again).

4. If you are using a jailbroken device, we cannot guarantee a smooth game performance.

If nothing helps, please contact us and provide the detailed info about your device and OS version. We will do our best to help.