1. Enter i Manager>Data monitor>Network management, disallow the apps such as video apps which can consume much data to use data network;
2. Go to Play Store>touch Menu button at the upper left corner>Settings>Auto-update apps, select Auto-update apps over Wi-Fi only;
3. Open Data saver mode while using browser such as Chrome. Go to Chrome>touch 3 dots icon at the upper right corner>Settings>Data saver, turn it on;
4. For Funtouch OS 3.1 and higher version, you can turn on Data-saving mode to restrict the apps to use data in the background.