Favorites (Selenium IDE) Requires Restart
A plugin for Selenium-IDE to have favorite test suites and open and execute the test suites with a single click
MeasureIt Requires Restart
Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.
Hide My IP is number one tool for hiding your IP and unblocking any web site!
Advanced Cookie Manager Requires Restart
A must have tool for Web Developers and Testers to Manage and monitor web cookies.
Export / Backup
Import / Restore
Available in English, French, Spanish, German and Italian languages.
A very simple extension for learning web page colors. Copy the RGB or Hex color code of any pixel displayed in your browser to the clipboard (in CSS/HTML format). Similar in function to Internet Explorer's color picker.
Wappalyzer is a browser extension that identifies software on websites.
Accelerate your SEO efforts on the fly. SEOquake is a free plugin for browsers that provides you with key SEO metrics for a specific page, along with other useful tools such as SEO Audit and many others.
The easiest way ever to change IP and browse anonymously! Just activate it with one click and it's done, you're browsing the web with a random HTTP or Socks proxy list from several countries in the world. No ads. 100% free to prevent web censorship.
JS Print Setup Requires Restart
Proxy Switcher Featured
Access to the complete Firefox's proxy settings right from a toolbar panel
Selenium Expert (Selenium IDE) Requires Restart
This plugin is my attempt to bring the wonderful world of inspections, tips, hints, fixes and refactoring to Selenese! The Selenium Expert goes through your selenium test cases suggesting improvements, giving tips and even lets you apply them.
This extension provides a list to almost all the settings that you may need to alter in order to enhance Firefox's speed.
Modify Headers Requires Restart
Add, modify and filter the HTTP request headers sent to web servers. This addon is particularly useful for Mobile web development, HTTP testing and privacy.
Autofill Forms Requires Restart
Autofill Forms enables you to fill out web forms with one click.
Auto Refresh Requires Restart
Auto Refresh will refresh or hard refresh any tab or group of tabs at individual or group intervals.
You can also customize your presets and save the ones you most use.
Emoji Keyboard Featured
A free Emoji Keyboard extension of the web tool http://emojikeyboard.org. This extension lets you input emojis right in the Firefox web browser. It also comes with an extensive search functionality that helps easily get emoji by keywords.
Charles Proxy Auto-Configuration Requires Restart
Configures Mozilla Firefox for use with Charles Web Debugging Proxy.
Image Zoom Requires Restart
Adds zoom and rotation functionality for images...
-Zawgyi-One script fallback fonts for Firefox (Android edition)
Addon installs Zawgyi-One font (Zawgyi-One.ttf under SIL OFL 1.1 license) that enables proper rendering of
Zawgyi-One script on all sites (Facebook, Twitter, Google, etc.),
YSlow Requires Restart
YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages.
http://yslow.org is the official open source website.