Sometimes you may notice that you have too many apps running and want to shut some down to save the battery and other times you may notice an app isn’t responding correctly. If that is the case, shutting the app down and restarting it will help it run better. Either way, it’s easy to kill an app on your iPhone.
To kill an app on your iPhone simply double tap the home button so that you can see the apps that are running and slide them from side to side to find which one you want to shut down. Then, if you are on iOS 7 you can shut the app down when you find it by swiping it up on the screen until the app disappears. If you have iOS 6 or earlier, hold down on the app until a red badge with a line through it comes up. When the app starts to shake and you see the red badge, tap on that to kill the app.
If the app doesn’t seem to want to shut down then hold the Home button for about six seconds to force it to quit the program and return to your main screen. If that doesn’t work, reset or restart your iPhone. This also works with other iOS devices.