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).
Adblock Plus Pop-up Addon extends the blocking functionality of Adblock Plus to those annoying pop-up windows that open on mouse clicks and other user actions.
With this addon you can translate any text to your own language with one click or hot-key. You can either translate the selected text, this way the translated text will overwrite the original selected text, or you can translate the full page too.
Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.
Reloads web pages every so many seconds or minutes. The function is accessible via the context menu (menu you get when you right click on a web page) or via tab context menu (right click on the tab)
A customizable mouse gestures extension which enables to execute various commands and user scripts with six types of gestures.
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!
Advanced Eyedropper, Color Picker, Gradient Generator and other colorful goodies...
Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.
(former Google Dictionary and Google Translate)
In-line dictionary for any word you point to or double-click; whole page translation of any web page in another language.
NewTongWenTang is a tool to switch display Chinese content between traditional and simplified glyphs (中文繁簡體互轉工具)
Show the IP address of the current page in the status bar. It also allows querying custom information services by IP (right click) and see location and avaiable vouchers for shopping sites. Additionally you can copy the IP address to the clipboard.
A Statusbar with speed, percentage, time and loaded size (similar to Opera's one)
With this Firefox add-on you can add a GMail icon to the toolbar. This button opens Google Mail (https://mail.google.com) webpage on a new tab.