App Center covers all apps compliant with platform guidelines, plans for flat fee paid-for apps revealed. Each listed app will have its own detail page, a no-strings-attached preview of the app`s functionalities for potential users. The main criterion for listing in the App Center is the quality of an app, defined as a combination of users ratings and engagement. Facebook users will be able to browse through a variety of mobile apps and then download them directly from App Store or Google Play.”]