Blocks annoying video ads on YouTube, Facebook ads, banners and much more.
Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
The Web Developer extension adds various web developer tools to the browser.
Displays a country flag depicting the location of the current website's server and provides a multitude of tools such as site safety checks, whois, translation, similar sites, validation, URL shortening, and more...
Use tamperdata to view and modify HTTP/HTTPS headers and post parameters...
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
Personas are free, easy-to-install "skins" for Firefox. Personas Plus extends that built-in functionality to give you even more control and easier access to new, popular, and your own favorite Personas.
AiOS lets you open various windows as sidebar panels, and quickly switch between them. So it put an end to the window chaos! In addition to bookmarks and history it opens dialogues such as downloads, add-ons and more in the sidebar.
StumbleUpon is the easiest way to discover new and interesting photos, videos, web pages and more, recommended by a community of experts. Tell us what you are interested in and we recommend page after page of amazing stuff you’d never expect to see.
Screengrab! saves webpages as images... but not for new versions of Firefox.
FF changes too fast and I don't have the time to maintain it anymore. Bugs have developed that I am not in a position to investigate.
Therefore, Screengrab is EOL.
A very compact & highly customizable theme that minimizes space consumed by menu & tool bars without hurting the overall usability. Supports Windows, Mac & Linux.
Add useful extra features to Gmail, like hierarchical labels, an unread message icon on your browser tab, file attachment icons, and more.
Collections are groups of related add-ons that anyone can create and share.Explore Collections