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).
Xmarks is the #1 bookmarking and open tab add-on. Keep your bookmarks, and open tabs backed up and synchronized across computers and browsers. Mobile phones with Premium access. Utilize LastPass to sync passwords!
Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.
FEBE (Firefox Environment Backup Extension) allows you to quickly and easily backup your Firefox extensions. In fact, it goes beyond just backing up -- It will actually rebuild your extensions individually into installable .xpi files.
The extension previously known as GooglePreview. Inserts preview images (thumbnails) and popularity ranks of web sites into the Google, Yahoo, Bing and DuckDuckGo search results pages.
3D in your browser! FoxTab brings innovative 3D functionality to your Firefox.
New! Top Sites for FoxTab (aka Speed Dial).
A no-clutter image viewer for Firefox that allows you to zoom, rotate and display images/videos against a custom background. ImageTweak is a must-have addon for any photographer or photography-loving user.