To fully close an app on iOS6, follow these steps:

  1. Return to the iOS home screen 
  2. Double tap the Home button on your device. A menu should slide open at the bottom of the screen 
  3. Press and hold the CSR Racing icon in this bottom menu
  4. After a second, a minus sign should appear at the top corner of the app icon. 
  5. Tap the minus sign to fully close the app. 
  6. Reopen the app.

To fully close an app on iOS7, follow these steps:

  1. Double tap the Home button on your device. You should then see screenshots of all open apps.
  2. Swipe the app you wish to close to the top of the screen and it will disappear.