The easy way to download and convert Web videos from hundreds of YouTube-like sites.
The extension previously known as GooglePreview. Inserts preview images (thumbnails) and popularity ranks of web sites into the Google, Yahoo, Bing and DuckDuckGo search results pages.
The original Gmail notifier for multiple accounts. Allows you to receive new mail notifications along with viewing account details including unread messages, saved drafts, spam messages, labels with new mail, space used, and new mail snippets.
Shareaholic is the easiest way to share & bookmark great content from anywhere on the web from one simple ALL-IN-ONE add-on. Works with Facebook, Twitter, Pinterest, Google, LinkedIn, E-mail and 200+ additional services.
A productive way to organize, read and share the content of your favorite feeds, blogs and news sites. Feedly offers a seamless transition from Google Reader.
Display all Google services as buttons or as a space-saving dropdown menu next to your address bar. Reach services like Gmail, Google reader, Google maps, Google calendar, and many more in a single click from your browser.
Add useful extra features to Gmail, like hierarchical labels, an unread message icon on your browser tab, file attachment icons, and more.
GMarks helps you sync & manage your bookmarks with Google Bookmarks...
Improve relevancy by up to 40% on Google and Yahoo! by automatically digging out results from as deep as page 100.
Note from Mozilla: This add-on has been discontinued. Try WebMail Notifier instead.
The original notifier for Gmail.
Display Wolfram Alpha results in Google searches.
No need to switch search engines when you can use both at once!
A compilation of some of the best Greasemonkey user scripts for YouTube in one interface.
Add useful extra features to Google Reader, like feed favicons, inline article previews, and unread counts in your browser tab with Better GReader.
Note from Mozilla: This add-on has been discontinued. Try Google Minimalist instead.
CustomizeGoogle enhances Google by adding information and removing unwanted information.