CSS Scan - Instantly check or copy computed CSS from any element for only ~95$
CSS Peeper - Smart CSS viewer tailored for Designers.
Hoverify - All-in-one browser extension to improve your web dev experience.
Purgecss - Easily remove unused CSS
LiveStyle - A real-time edit tool for CSS, LESS and SCSS.
Tailwind CSS - A utility-first CSS framework for rapidly building custom user interfaces.