how to close apps

press the home button

You stop apps from running by double pressing the home button, finding the app in the lower row, and cicking the minus sign in the upper left.

You do close apps as roaminggnome said. I'm just not sure what your real question is.

"You stop apps from running by double pressing the home button, finding the app in the lower row, and cicking the minus sign in the upper left."

- apps (esp 3rd party ones) are not necessarily running in the background in the first place. so you're not "stopping" anything. the list you see is a recently used apps list.

For those who prefer visual demonstration, this video shows you how to do it in IOS7:

How To Close Apps On iOS7 (iPhone/ iPad/ and Others) andSave Battery Life

http://youtu.be/4cQNjSsd1xg