To close the iPad app, you must get to your task bar. Do this by pressing down the home button at the bottom of your iPad twice in a row. (The home button is the circular button you use to close iPad apps.) When you double click the home button, a task bar will appear showing your most recently used apps.
Touch one of the app icons and hold your finger against it until the icons begin to shimmer. A red button with a minus sign will appear at the top of the icons. When you see this button, you can release your finger and then simply tap the button for any app you want to close.