CSS Peeper - Smart CSS viewer tailored for Designers.
Sketch Tricks - Articles for Sketch
Tailwind CSS - A utility-first CSS framework for rapidly building custom user interfaces.
The Good Workshop - TGW helps experts plan, run, and track UX, CX, Product and innovation workshops, fully automated and straightforward user experience.
Purgecss - Easily remove unused CSS
Git Sketch Plugin - Version control for designers