(X)HTML5 Checker

Gridify - Keyboard Link Selector

Select any link, image, input box, or a selectable region on the current page without using the mouse just by a few keyboard hits

Rating: Total number of ratings: 1

Colored favicons for Salesforce

Make the favicon in different color based on which salesforce instance your are loggen into.

Rating: Total number of ratings: 3

Font Inspector

Click on any HTML element to get the font info in a popup!

Rating: Total number of ratings: 6

Помощник диагностики

Rating: Total number of ratings: 27

Web Developer

Adds a toolbar button with various web developer tools. The official port of the Web Developer extension for Firefox.

Rating: Total number of ratings: 137