Usability.gov - Resource for user experience (UX) best practices & guides
Rage Grade by FullStory - Benchmark your customer frustration
UsabilitySquare - Get unbiased, instant feedback how to optimize your design.
UXsniff - Track user behavior on your website and improve conversions with UXsniff: the user experience watchdog that looks out for you.
Digital Psychology - Elevate your product using psychological techniques
UserBit - A full-stack qualitative research platform for UX & product teams.