Develop and export quick prototypes.
It's great, but no emmet. Isn't that kind of essential if you're going to 'quickly' prototype html and css? Does anyone actually type native html anymore? It's painful.
https://gofullpage.com
http://colorzilla.com/
https://callumlocke.com
Chrome Enterprise Team
https://developers.google.com/web/
https://www.seoquake.com/
https://clearcache.io
http://www.seo-extension.com/
https://modheader.com
https://postman.com
stylus.openstyles
http://seleniumhq.org/