In a few weeks time, Facebook will launch its own app store in an effort transform the social network into a premier app destination. App Center will be spread out across the desktop, Android and iOS. It will contain both free and paid apps along with links to Google Play and iTunes should an app need to be installed on devices before they can be used.
Facebook isn't necessarily attempting to cut out other app stores altogether. Its real goal is to utilize social apps that integrate with Facebook in order to keep users engaged for a longer period of time. Simply put, if an app doesn't have Facebook integration, it won't be found in App Center. Facebook will, however, make the App Center look like a traditional app store by requiring every developer to create an app details page. The app details page will gives users a basic overview of what to expect from the app.
Facebook is also trying to keep app quality high with App Center. They will use metrics such as ratings and user engagement to determine which apps are displayed or not. This should encourage developers to work hard at making their app the best it can be. If they don't, they'll be missing out on the opportunity to be seen by millions of potential users.
App Center will contain both free, free-to-play and one-time paid apps. It appears the apps that require a one-time payment will only be accessible on Facebook's full site.