My favorites are Wappalyzer (https://wappalyzer.com/) for peaking under the hood of my favorite sites, and vimium (https://vimium.github.io/) for faster browsing. What are yours?
Tried many extensions for vim-like control of my browser, but pentadactyl is by far the most usable. Even without any customisation, just pressing 's' and instantly being able to search with auto completion ('b' for the same across all open tabs) is incredibly useful.
