A few add-on that I frequently used, and will always install with a new FireFox.
Note: If you are encountering the Connecting... problem see instructions below.
The updated, fully supported IE Tab. Embed IE in a Firefox tab. IE Tab Features: FF 4+ support, IE 7-9 compatibility modes, old IE Tab settings import.
The most beautiful yet the simplest add-on that makes a strong colorful appeal. Colors every tab in a different color and makes them easy to distinguish while beautifying the overall appearance of the interface. For Seamonkey & Flock. An essential. F...
Enables Adobe Acrobat-style grab and drag scrolling, Flick gestures, and Momentum scrolling in Firefox. Useful for (older) pen or touchscreen-based devices for which these gestures are not natively supported. Not useful on Windows 8 touch devices.
Extends the function of the drag-and-drop mouse gesture so that it can be used to load URLs, do a web search of selected text on a page, or save an image on a page. The successor to Super DragAndGo.