One Click Test - Tool for quickly testing your design layout in one click.
browserling - Live interactive cross-browser testing from your browser.
XPRS - Free website builder - making web design like Lego™. No code
BrowserStack - BrowserStack is a software testing platform for developers to comprehensively test websites and mobile applications for quality.
Dimensions Toolkit - Chrome Extension for designers to test responsive websites.
Browsershots - Browsershots makes screenshots of your web design in different browsers.