Here is a list of items that are tested in your Windows 8 App. If you are in Southern California, please email these posts for more information on getting a token for your app by June 30, 2012!
App bars provide the user with easy access to commands when they need them. Users will be familiar with the pattern and will expect consistency across apps. You should
Ensure your app bars are organized, consistent, de-cluttered, and work well across all view states.
App bars should not have navigation elements in them.
To learn more and have a great app bar follow the guidelines for app bars.