On your old IOS you would double tap your home button to bring up a list of open apps, then hold down your finger on the icon for a few seconds to bring up a red X that would let you force close each of your iPhone Apps. I was totally confused after updating my iPhone to the latest IOS 7 as to where this feature was. Holding down on the open app icon did nothing, until I found out you have to swipe up to stop the app from running on IOS7.
POWER USER TIP: You can close out of multiple apps at once by swiping up with three fingers. This allows you to close out of three apps at once. Alternatively you can use one finger to get rid of one app as noted below.
Step 1: Double tap your home button to bring up your open apps
Step 2 : Swipe up (towards the top of the screen) on the app and it will close!
IMPORTANT: You can close out of three at a time by swiping with a three finger gesture!
There, now that you found out how to close an IOS7 app, you realize that wasn’t too hard after all!