going through this very helpful list of firefox add-on webextension porting statuses, which also lists already-existing WE alternatives

https://docs.google.com/spreadsheets/d/1TFcEXMcKrwoIAECIVyBU0GPoSmRqZ7A0VBvqeKYVSww/edit#gid=0

many key add-ons are not on the official FF add-on site yet, so this doc is much better than trying to browse that site