For Firefox: uBlock origin (of course)

Privacy Badger - controls which sites are allowed to use cookies

Mind the time - tracks time spent on various Web sites

Video DownloadHelper - detects media and allows you to download and transcode it.

Bitwarden - password manager

I don’t know how valid this is, but I heard county and district councils use government bonds to secure more favourable loan terms. When Liz Truss upset the UK bond market the cost of borrowing rose as the value of their bond assets dropped. The county council where I live is now spending as much on servicing debt as it is on fixing roads. (Roads, although not the most important responsibility of local government, are a visible indicator of their capability.)

Browsers made the Internet usable for the general population. The Internet as we know it would have remained a network for academia, governments and large corporations. Smartphones would not have been developed. Without a reason for everyone’s homes to be connected to a high speed network, TV would remain the remit of cable and satellite broadcasting - no streaming services.