The easy way to download and convert Web videos from hundreds of YouTube-like sites.
Download all the links, movies and audio clips of a page at the maximum speed with a single click, using the most popular, lightweight and reliable external download managers.
Restyle the web with Stylish, a user styles manager. Stylish lets you easily install themes and skins for Google, Facebook, YouTube, Orkut, and many, many other sites. You can even customize Firefox and other programs themselves.
The Web Developer extension adds various web developer tools to the browser.
FireShot Webpage Screenshots captures pages entirely. Demo: http://bit.ly/RlBQMV
The screenshot can be quickly captured and:
― Saved as Image or PDF
― Sent to clipboard
― Annotated *
― Uploaded *
― E-Mailed *
* OS Windows only
Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.
— Open web pages saved with Internet Explorer or other browsers (MHT)
— Save many tabs, video and audio reliably, in a single ZIP file (MAFF)
— Return to the original site you saved a page from, and more!
HTML Validator is a Mozilla extension that adds HTML validation inside Firefox and Mozilla. The number of errors of a HTML page is seen on the form of an icon
For Firefox 23+, you need 0.958 (under review)
Secure Login is an extension for Firefox integrated password manager.
DOM Inspector is a tool that can be used to inspect and edit the live DOM of any web document or XUL application. The DOM can be navigated using a two-paned window displaying a variety of different views on the document and all nodes within.