Microsoft and Facebook announced this morning the availability of the new Windows 10 Facebook app. While the app is not a true UWP as it uses Facebook's own Osmeta developer tool it does have many new features and that familiar Windows 10 design.
Version 188.8.131.52.191 is now live in the Store, and it re-uses the link for the original Facebook app for Windows 8.1
The new version of the app features an in-app browser, GIFs for group conversations, and direct messaging along with Live Tiles that highlight new information without having to open the apps. Early beta testers had a lot of good things to say about it, but now you can try it yourself.
A mobile version of the app is expected later this year and it will replace the current one on the Store.