Facebook Design - Resources for Designers from the Facebook Design team
Anima App - Design, get feedback, convert to code, publish, iterate.
Facebook - Connect with friends, family and other people you know. Share photos and videos, send messages and get updates.
Sketch Repo - Collection of resources for anyone who uses Sketch
Straple - An end to end design system in Sketch and ReactJS
Auto-Layout for Sketch - Responsive design for Sketch