Q: Hi..I just downloaded the new ios7 on my ipad, how do you close the open apps?

How to Close Apps

Double Tap the Home Button... Then swipe the App (not the icon) Upwards... Tap the Home Button when finished.

From Here  >  http://support.apple.com/kb/HT4211

You're Welcome.

Enjoy

You can also use th multitasking gesture of four fingers on the screen to slide up the window of any open app you're using and that will cause the screen to display windows of all the apps you have open. Scroll through them horizontally And flick up with one finger to close the app. I like using this method because it saves wear and tear on the Home button.

Cheers!

Sorry, forgot I was in the iPhone section of discussions. This only works for the iPad. For the iPhone you must do the double-click as described by AnaMusic.