Firefox Multi-Account Containers lets you keep parts of your online life separated into color-coded tabs that preserve your privacy. Cookies are separated by container, allowing you to use the web with multiple identities or accounts simultaneously.
Make the browser forget website data (like cookies, local storage, etc.), except for the data you want to keep by adding domains to a whitelist, graylist, blacklist, or redlist.
An easy-to-use tab reloader with custom reloading time settings for individual tabs
Edit the contents of a web page prior to printing or saving. Elements in the web page can be edited, formatted, hidden or deleted. Unwanted content, such as adverts and sidebars, can easily be removed.
Squared tabs, application button menu, add-on bar, small button view, old search and many more 'old' features for 'Firefox 29-56' only, not for Firefox Quantum (57+)! >Latest builds only on Github!<
Tab Groups are an easy way to organize a lot of tabs. You can visually group related tabs, switch between groups, and quickly search through all of your tabs to switch to a specific one.
Play game Flappy Bird when you open a new tab. Try to fly the bird as far as you can without hitting a pipe!
Short, Vim-style keyboard shortcuts for browsing and navigation, for a near mouseless experience.
Download video from any Youtube video in High definition HD.
Open a mobile view of a page in the sidebar
You can capture a screen shot by selecting an area or capture the whole/visible webpage. Then edit and save it as an image file.
Automatically suspends unused tabs to free up system resources