Sometimes there is no actually problems, but still there are a few things that will effect your game performance.
THINGS TO CHECK ON REGULAR BASIS
1. Install updates (which includes system updates)
2. Before you play, close all other apps and restart (this clears the cache)
3. Turn off Bluetooth Sharing, if you are not using it during the game
3. If your storage is almost full or less than 1 GB (delete unnecessary stuff)
4. Refresh your app and game data. Your profile is connected to either a Google Play or Apple App Store account. Delete the app and data, then reinstall the app and login with same account. (This refreshes everything)
5. If all this fails, then blame it on karma.
NOTE: If you are running multiple apps at the same time, they still use the processor in the background and can cause lags, crashes and other glitches. This includes automatic notices in the background, like email and text notifications, weather notices, and anything that is checking for current information.
APPLE iOS SPECIFIC TWEAKS
Check which apps are pulling data in the background. Each of these options take a big toll on your game performance.
1. First go to Settings > Notifications, and look through the list. Turn off unneeded notification or at least pause them during the game.
2. Another spot is Settings > General > Background App Refresh. Turn apps completely off or keep only what you critically need.
3. The next spot is Settings > Privacy > Location Service. Turn off all or at least adjust each app so it is checking your location only “While Using”.
4. For an advanced trick, temporarily silence calls and alerts from Settings > Do Not Disturb and enable it. You can also quickly access it from the “swipe up” menu.