Draw a ruler across any webpage to check the width, height, or alignment of page elements in pixels.
Tabby helps you manage a lot of windows and tabs easily; it can help you open, close, move, pin, and do many other things on tabs and windows quickly. With Tabby, you can even save all you windows and tabs for later with just one click!
Download YouTube videos in all available formats and extract the original audio files
Get international weather updates (via AccuWeather.com) displayed right in Firefox with this highly customizable extension.
Ghostery is a powerful privacy extension. Block ads, stop trackers and speed up websites.
Automatically learns to block invisible trackers.
Protects you against tracking through "free", centralized, content delivery. It prevents a lot of requests from reaching networks like Google Hosted Libraries, and serves local files to keep sites from breaking. Complements regular content blockers.
Finally, an efficient blocker. Easy on CPU and memory.
The easy way to download and convert Web videos from hundreds of YouTube-like sites.
The best security you can get in a web browser! Allow potentially malicious web content to run only from sites you trust. Protect yourself against XSS other web security exploits.
LastPass, an award-winning password manager, saves your passwords and gives you secure access from every computer and mobile device.
A secure and free password manager for all of your devices.
RoboForm, the #1 ranked Password Manager makes your life easier by remembering passwords and logging you into websites automatically
Offline P2P encrypted password manager & authenticator. Auto-fill Two-Factor Authentication (2FA) tokens.