Before you submit your app for certification and listing in the Windows Store, use the Windows App Certification Kit (ACK) to test your app and make sure it's ready for submission.
The Windows SDK includes the Windows ACK to test your app for the Windows 8 Certification Program and the Windows 7 Logo Program.
To self-test your app on Windows RT, use the separate Windows App Certification Kit for Windows RT download.
November 16, 2012: Windows ACK 2.2 is now available; this version is required for app submissions to the Windows Store as of December 11, 2012. Windows ACK 2.2 includes bug fixes as well as three new tests:
Windows App Certification Kit (Windows SDK)
Note: the Windows SDK for Windows 8 cannot be installed directly on the ARM architecture. You can install the Windows SDK on an x86 or x64 platform to build applications that target the ARM architecture, and then use the Windows App Certification Kit for Windows RT download to test the app on that platform.
Windows App Certification Kit for Windows RT