Flinto - The prototyping tool designers have been waiting for.
SketchCasts - A weekly screencast, all about how to use Sketch
Base UI Sketch Framework - Huge set of everything you need to design and prototype
Glyphy - Copy & paste fancy fonts + cool symbols ☞✺✐™
Remake - A way to make web apps with just HTML & CSS
Enzyme - Enzyme is a JavaScript testing utility for React.