Responsinator - Designed to test responsive websites on different devices.
One Click Test - Tool for quickly testing your design layout in one click.
SlideRule UX Design Path - Curriculum of Online Courses To Learn UX Design
XPRS - Free website builder - making web design like Lego™. No code
BareMetrics - SaaS Analytics for Stripe
Dimensions Toolkit - Chrome Extension for designers to test responsive websites.