This is such a handy tool whenever you are curious about the technologies used on a website. Whenever I find a website interesting, I can easily peek at what technologies they used and it also greatly helps while developing my own websites.

It's amazing

Best extension to detect technologies but it's quite heavy in performance and sometimes a bit buggy.

It does not work most of the time. Use BuiltWith instead.

Very handful, but requires suspiciously many permissions.

Wappalyzer has always been one of my 'must-have' add-ons, but recently it became too heavy on resources!
I find my laptop fan spinning too much while doing nothing, and after I opened Firefox' `about:config` I found this addon uses a most of resources.

I use it, Very helpful and easy to use.

Consume mucha memoria y energía después de un tiempo activo.