Microsoft uses a beta version of the Facebook app to publicly test new and updated features of the app. Updates for the beta version of the app are released on a near weekly basis, but the main release is updated only periodiocally (the last main release was in October). This dual track approach is an effective way to maintain a high development cadence, without annoying the majority of users with a never ending stream of updates.
Here's how we described the updates when they were added to the beta version:
The new Facebook chat toast notifications arrives as part of a wider ranging update to the app's notification system, which is designed to improve the overall reliability of incoming notifications.
The more obvious element of the new update is the app's redesigned Live Tile implementation. Both the look and feel of the primary and secondary Live Tiles has been updated. Secondary Live Tiles for chat, events, groups, page, and photo albums all draw content from the respective section of Facebook, with a strong visual element added by using relevant background images whereever possible. The key benefit of the new Live Tile is that more information can now be seen, at a glance, on the Start screen.
In using the beta version over the last month the biggest change in practical terms has been the improved speed and reliability of notifications in general. Since this is a key part of any mobile Facebook experience it's a very welcome addition and make this latest update an essential download for those that regularly use the Facebook app to complement the functionality built into the People Hub.
The new version also includes enablers that lets third party app developers integrate Facebook Login support into their apps. This is an important feature as an increasing number of games and apps are relying on Facebook to provide an identity service, rather than setting up their own. Establishing a users identity can be vital for activating online and other connected features in games and apps (and users tend to prefer using an existing identity account too). More details on the Facebook Login feature and how developers can integrate it into their own apps is available on the Windows Phone Developer Blog.
Windows Phone Store description:
Facebook for Windows Phone v5 has been completely overhauled, with faster performance, a new user interface, improved navigation, support for multiple resolutions and tile sizes, and more.
This update includes performance improvements and bug fixes.
v5.2 Additions:
• Faster and more reliable notifications
• Toasts for Facebook chat
• Redesigned primary tile
• Redesigned secondary tiles for chat, events, groups, pages, and photo albums
• Messaging improvements
• Performance improvements
• Support for additional languages
Facebook is a free download from the Windows Phone Store.