Samsung galaxy S4 allows multitasking and going in between apps. That is you can listen to you music and email at the same time. But once you are done emailing and you go to home screen or any other app your previously used apps are still running in the background – which means your battery is getting drained and your data plan is being used without being you aware of it. To save battery and your data plan (of course when you are not near a WiFi hot spot) you need to complete close your apps running background.
This is how you would do that:-
1. Hold and press your Home button for a few seconds.
2. The list of all the apps recently opened and still running in the background is opened.
3. Tap on the “Task Manager”
4. Tap the “Active Applications” tab if its not opened in Task Manager by default.
5. Tap the End button for all the apps that you want to close completely from running in the background.
6. If you want to close down all the apps running in the background you can tap the End All button.
And you are done.