When your game closes for no apparent reason we call it a “crash”. There are several reasons that may cause mobile apps to crash or freeze.

Power saving mode, low RAM memory, and an outdated operating system, CPU, and/or router can worsen your game's performance in certain cases.

1. Find a place where you get a strong Mobile Data or WiFi signal (the latter is recommended). Free or open WiFi networks usually provide low bandwidth and are not ideal for playing. Reboot your device regularly (once per week) to fix IP and DNS issues.

2. Some devices suffer from a low-memory issue and most perform poorly once they hit around 80% of their storage capacity. You can try to back up your data and make a factory reset, or just delete everything you don’t need, like apps, files, images and videos to improve performance.

3. Having resource-hungry apps running in the background can really cause a huge drop in battery life and performance. Live widget feeds, background syncs and push notifications can cause noticeable lag. Regularly close apps and services running in background to release some RAM for your game performance.

4. As a last resource, uninstall the app (make sure your account is saved with Facebook, Apple ID, or Google Play first), and install it again.

Hope this helps!