Q: How do I stop an app or shut it down after I'm done using it?

Double tap the home button. The app icons and preview windows will line up on the screen. Scroll sideways if needed to get to the app in question. Flick its preview window up and off the screen. Single tap the home button or home screen preview window to exit the mode.

Close apps

1. Double tap the home button to bring up the multi-tasking view

2. Swipe the app's windows upwards to close

3. The app will fly off the screen

You tap the Home button and open the next application. It's very rare that you'd need to perform the above described procedure.

http://support.apple.com/kb/HT4211

Best of luck.

True. Generally, you just hit the home button and exit the app. It'll close on its own if the system allocates power elsewhere....for example shutting down apps 1 and 3 when  app 12 needs the RAM apps 1 and 3 are using.

Some people do choose to close down unncessary apps to help on battery usage. I have an iPad 2 and iOS7 does push it, so I choose to go in and close down unneeded apps just to help wiht system resources.