The game crashing can occur due to a number of reasons, here are a couple things you can try to resolve the issue on your own.
- Ensure your devices storage space isn't full
- If you are running alot of apps on your device close them to ensure your device memory isn't being filled up.
- Restart the device
- Ensure you have updated to the latest version of the application
- Ensure you have updated your device to the latest OS
- Ensure you have updated the Google game services (Google Only)
- Ensure you are using a device which isn't jailbroken or has been altered in anyway