Description from extension meta
Some vim like keymappings for Firefox and Chromium browsers.
Image from store
Description from store
The add-on has some navigation keymappings inspired by Vim:
j : down
k : up
f : scroll down
b : scroll up
gg : scroll to top
G : scroll to bottom
Shift + ss : change current tab to https://duckduckgo.com
Shift + xx : change current tab to https://google.com
Shift + hh : go back
shift + ll : go forward