Designers and developers who want the apps they’re working on to look more like Facebook’s own are in luck. The company now has a site dedicated to its design principles.
Rather than serve as an educational portal for schooling everyone in the art of design or development, Facebook has chosen to pack design.facebook.com with resources.
We don't shill.
Check out TNW's Hard Fork.
There’s Sketch or Photoshop files for an iOS GUI, and a link to Facebook’s prototyping tool, Origami. There are also links to Facebook’s Medium page about design, and a tool for slipping your app imagery into a hands-on photo.
It’s already a pretty handy repository for designers and developers, and worth bookmarking; you can expect Facebook to add to this site regularly.