Warning! Windows 8.1 RTM users, please refer to the Close Threshold for Windows 8.1 app!
Close Threshold for Metro Apps is a must-have tool for all Windows 8 users. It allows you to improve ways of Metro apps closing. You will able to do much smaller mouse movements/touch "swipes" to close any app.
Set sliders to left, and it will be not nessesary to drag Metro apllication to the bottom edge of the screen! After you click on "Save settings" button Windows Explorer will be restarted and you will able to close Metro application near the top edge of the screen.
I have prepared a video to show you how is it works: