Here's how you can shut down an app in iOS 7.
1. Press the Home button twice to see the multitasking screen.
2. Tap on the app you want to close, swipe up and release it.
3. The app will disappear from the multitasking screen and it will be shut down.
You can also swipe left or right to move through the list of open apps on your iOS 7 device. The multitasking iOS 7 makes it very easy to see the apps you have open, and to close them.