Firefox Extensions

Markr.app
Lets you highlight & capture content on web like a marker
Restyler
FF/Chrome Extension for smart style/dom manipulation
Extension Rank
Web app where users can discover browser extensions.
CSS Scan Pro
The fastest way to inspect & copy the CSS of any element
Color Sets
Tools for designers and developers.
Adobe.lol
Stupid extension that replaces "Adobe XD" with "Adobe 😆️"
Meta Preview
A Browser Extension to preview Meta Tags
CSS Scan
💫 Instantly check or copy 📦 computed CSS
Acorn Bookmark Manager
Reminders, Smart Lists & Full Customization
History Search
Desktop search for your stuff online
Z-index
Always-on-top web videos for Mac and Windows
Make Medium Readable Again
A browser extension to make Medium less annoying.
Klart
Save a link and screenshot one anything