I don't know of too many browser extensions, but the ones I do know are good, and you should probably install them. I have all of these on my desktop and phone! Also, you should use the Zen browser on my PC. It's basically Firefox but it looks cooler and has some nice features.
Rest in peace Grepper, my formerly second favorite extension :,( The idea was basically that users could submit an answer to a question which would show up before any results if someone googled roughly that question. This was most useful for code, because you could search for reverse list js
or something and figure out how to do it without having to click on any link and accept cookies on MDN web docs or whatever. About 2025-5-12 it stopped working, and as far as I know there hasn't been any explanation from the developers.