UXTesting - Discover how your mobile users feel
Checklist Design - The best UI and UX practices for production ready design.
Startup Timelines - How the frontpages of famous startups changed over time
Uxcel - The easiest way to learn UX/UI design
Really Good UX - A library of screenshots for UX inspiration
UXsniff - Track user behavior on your website and improve conversions with UXsniff: the user experience watchdog that looks out for you.