Have you closed down the apps in your multi task bar?
Do the four finger swipe up or double tap the home button to reveal your multi task bar along the bottom. It will show all the apps that you have opened at one time or another. Long press one of these apps until they start to jiggle and red minus signs will appear above them all. Press all the minus signs, this will close them, not delete them. It's a good idea to do this regularly just to keep them all running smoothly, I do mine every night. Check and see if it is operating now.