Penetration Testing Kit
Attention! This version is no longer supported. Use /firefox/addon/owasp-penetration-testing-kit/ extension instead.
921 users
Slither.io Mods, Zoom, Unlock Skins, Bots
The Best Mod and Extension for Slither.io! Mod Zoom, Play with Friends, Skins, Custom Skins, Bots
913 users
Resize Window & Viewport
Resize browser window or viewport to desired screen widths. Firefox's Responsive Design Mode (Ctrl + Shift + M) is great for mobile devices emulation.
906 users
Flash Debugger
Debug Flash/SWF/Flex files on the web. Edit properties and inspect elements on the fly. View log output inside the extension. Run AS3 code against the active SWF. Profile memory consumption and much much more...
887 users
Save to Trello
This firefox extension allows you to Create a Trello card from any webpage (including Gmail/webmail) / Ideal for Inbox Zero. You can save the current page to Trello. When you find something in Firefox that you want to view later put it in Trello.
886 users
Mangools SEO extension
Speed up your SEO right in your browser: See the key SEO metrics, popularity trends, competitor's keywords, backlinks and on-page SEO insights of any domain or URL. Have the power of Mangools SEO package any time you need.
871 users
SEO Inspector
SEO Inspector scans the active page and applies a set of customizable rules to its contents. The results of the scan are displayed on a simple, elegant interface for manual inspection.
868 users
Block Yourself from Analytics
Block your Google Analytics™ activity for the websites you own, no more false stats.
856 users
IP Whois
View info about IP, DNS records, SSL, country flag, domain whois, location, stats and more of any website.
855 users
Simple Link Checker
Redirect Link Checker will check all links on your page to find broken and redirect links
846 users
ASBPlayer: Learn with Subs
Language learning subtitle player for streaming platforms like Netflix, YouTube, and more.
834 users
Transparent standalone images
This add-on renders standalone images on a transparent background, so you can see the image in all its glory!
829 users
ProxyControl
Manage setting of connect of proxy in your browser so quickly and so easily as you want.
827 users
Open With Photoshop
Open With Photoshop is a new companion for web and graphic designers to open up any web image with Adobe Photoshop via a single and quick mouse click.
815 users
Scrum for Trello
Scrum for Trello adds functionality to the awesome trello.com for use in Scrum projects. Add estimates or record time-spent directly on Trello cards. Shows sums at the top of each list and the top right corner of each board.
809 users
Color Picker
A simple color picker extension. Easily pick any color on the screen, view history of picked colors, and copy or clear them with a single click.
809 users
