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
App Launch Checklist - Planning tool for launching your app successfully
UX Check - Easy heuristic evaluations on your website (chrome ext.)
ASO Tools by AppFollow - Tools for App Store Optimization in App Store & Google Play