AbTest.io - A free url shortener with A/B testing features
DesignMunk - Landing Page Inspirations
GoodUI Evidence - People's A/B test results that show which UI ideas work best
SiteSee - Curated gallery of beautiful, modern websites.
PreFlight - Preflight is an Automated Web Testing tool. Allows everyone to automate Web UI tests.
Muzli - UI/UX and Design Inspiration Chrome Extension