Really Good UX - A library of screenshots for UX inspiration
Rage Grade by FullStory - Benchmark your customer frustration
Usability.gov - Resource for user experience (UX) best practices & guides
Shuffle for Bootstrap - Bootstrap drag and drop builder for busy developers.
UX Check - Easy heuristic evaluations on your website (chrome ext.)
Tailwind CSS - A utility-first CSS framework for rapidly building custom user interfaces.