AT-UI - UI library for developing powerful web interfaces
Faviconer - Faviconer.com, or favicon generator, is online tool for creating favicon.
Sketch Repo - Collection of resources for anyone who uses Sketch
ConvertICO.org - Create icons from png, jpg or bmp images easily.
Git Sketch Plugin - Version control for designers
Ordinatore - Those who want to tidy up their Macs will surely love this application.