HeadingsMap
The extension generates a document-map or index of any web document structured with headings and/or with sections in HTML 5. It shows the headings structure, the errors in the structure (ie. incorrect levels), and it works as HTML5 Outliner too.
6,037 users
Theme Font & Size Changer
Theme Font & Size Changer lets you change the global font size and font family used for the user interface in Firefox. Design your browser with your favorite font.
5,817 users
Adblock Plus
One of the most popular free ad blockers for Firefox. Block annoying ads on sites like Facebook, YouTube and all other websites. Adblock Plus blocks all annoying ads, and supports websites by not blocking unobtrusive ads by default (configurable).
3,184,827 users
Stylish - Custom themes for any website
Stylish lets you customize any website with custom user styles (themes for websites). Choose from the largest userstyles library to change the color scheme, background, and skin for Google, Facebook, YouTube and many, many more sites.
24,785 users
ColorfulTabs
The first addon you should be installing on a fresh Firefox install. A must have. The most beautiful yet the simplest add-on that makes a strong colorful appeal. Colors every tab in a different color.
11,499 users
Web Developer
The Web Developer extension adds various web developer tools to the browser.
75,715 users
