Sketch Repo - Collection of resources for anyone who uses Sketch
Invision - Prototyping and collaboration for design teams
Gmail Add-on Design Kit - A simple Sketch library to speed up Gmail Add-on designs
Mockuuups Studio - Fast and easy way to create product mockups on macOS, Windows and Linux.
Charts by ls.graphics - The most comprehensive collection of charts for Sketch
Craftwork - A collection of User Interface resources made by Craftwork