Screenfly : Test Your Website at Different Screen Resolutions
Site Valet : Web Tools for Quality, Accessibility, Standards Compliance.
webhint : webhint is a linting tool that will help you with your site's accessibility, speed, security and more, by checking your code for best practices and co...
Maestro : Maestro is the easiest way to automate UI testing for your mobile app.
Diagnostic.css : Diagnostic.css is a stylesheet which allows the user to test for common errors in a page's markup.
Also : https://github.com/karlgroves/diagnostic.css
The mobiReady testing tool evaluates mobile-readiness using industry best practices & standards.
