Personas are free, easy-to-install "skins" for Firefox. Personas Plus extends that built-in functionality to give you even more control and easier access to new, popular, and your own favorite Personas.
When you find something on the web that you want to view later, put it in Pocket. It automatically syncs to your phone, tablet or computer so you can view it at any time, even without an internet connection.
Lightbeam is a Firefox add-on that enables you to see the first and third party sites you interact with on the Web. Using interactive visualizations, Lightbeam shows you the relationships between these third parties and the sites you visit.
Multiple account (or label) Gmail notifier (without storing passwords)
This extension allows you to export your saved passwords and disabled login hosts using XML or CSV files that can be imported later.
Screen capture Web Page, selected region or whole browser window, edit screenshots and save the images to Local File or Google Drive. Edit screenshots in a very user-friendly interface with the different tools.
Adds download link/button to all SoundCloud tracks. Plus feature to drag and drop any SoundCloud link into the downloader-toobar to start downloading track.
DuckDuckGo is the search engine that doesn't track you. We also have smarter answers and less clutter. This extension makes DuckDuckGo available in the address bar, search bar and right-click menu. Also adds a handy toolbar button with more features!
Install the MEGA Firefox extension for vastly improved download performance. It will allow you to batch-download an unlimited number of files without any size restrictions from MEGA.
Evernote Clearly makes blog posts, articles and webpages clean and easy to read. Save them to Evernote to read anywhere.
With this Add-on, you will have quicker and easier access to all Facebook emoticons and stickers.
FEBE (Firefox Environment Backup Extension) allows you to quickly and easily backup your Firefox extensions. In fact, it goes beyond just backing up -- It will actually rebuild your extensions individually into installable .xpi files.
Firefox OS Simulator is a test environment for Firefox OS. Use it to test your apps in a Firefox OS-like environment that looks and feels like a mobile phone. After installing it, go to Web Developer > Firefox OS Simulator to access its features.