You can use this process to close/force close a single app or all apps running on the device.
Double-click on the Home button on your iOS device. This will show all of the apps running on your device.
Do one of the following based on the iOS version on your device:
iOs 6.x and older: Tap-and-hold on one of the app icons until all the icons appear to "shake" and you see a red circle with a white minus sign. Tap on the minus sign for each app.
iOS 7.x: Tap on each app and swipe your finger up and off the screen.
Press the Home button.
Press the Sleep/Wait button until you see slide to power off.
Swipe the slide to power off slider. The device will perform its shutdown operations and then power off.
Press the device's Home button and the Sleep/Wait button simultaneously until the silver Apple icon appears. If your device is in portrait mode, the Home button will be at the bottom of the device, and the Sleep/Wait button will be at the top-right of the device.
troubleshooting, iOS, pos