• Material UI – Combo of React components and a Less CSS framework to implement Google’s Material Design ideas, just in case you’re note enough on the bleeding edge yet.
  • Hound – Commercial CI service from Thoughtbot that concentrates on reviewing your code for style violations and posting them straight to your Github repo.
  • A Guide to Speeding up Your Rails Test Suite – A variety of small tweaks & tips that can add up.
Read more at the source