SketchCasts - A weekly screencast, all about how to use Sketch
TryMason.com - Make front-end features, faster
Base UI Sketch Framework - Huge set of everything you need to design and prototype
Front-End Checklist - The perfect Front-End Checklist for modern websites ๐
Framer - ๐ฅ Design real websites right on the canvas.
Front-End Developer Handbook 2017 - Learn about the practice of front-end development