[dvcc]

First thought was that this should be a grunt plugin, then I read the comments. Here it is: https://github.com/addyosmani/grunt-uncss

[brokenparser]

I thought there should be a Gulp plugin, and then I found this: https://www.npmjs.org/package/gulp-uncss/

[ehynds]

I thought there should be a Broccoli plugin, and then I found this: https://github.com/sindresorhus/broccoli-uncss