This is why Google brought up the option of data usage in Android 4.0 which shows you which apps and how much data has been used over mobile network and Wi-Fi. It also gives you a quick summary of which apps use how much data when in the foreground and when in the background over which network.
If you think apps are using a lot of background data, restrict them from using any. How? Follow the very simple steps below.
- Go to Settings > Data usage.
- Tap the 3 dots icon at the top right.
- Check “Restrict background data” box.