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