While existing legacy desktop style applications can be distributed using the traditional methods (as described in the Creating installer packages recipe), the only way to distribute Windows Store apps will be via the Windows Store, and they must pass a certification process for that to happen.
Certification is the process by which Microsoft ensures that apps available in the Windows Store will meet certain performance and quality standards. As a developer, the Store makes it easy for customers to obtain and install your app. In this recipe, we'll look at how the certification process works. Since apps for Windows 8 can only be maintained at this point, we'll focus on creating a new app for Windows 8.1.