Mockingbird : Mockingbird is an online tool that makes it easy for you to create, link together, preview, and share mockups of your website or application.
Ready for Rails 4? : Check easily whether a gem is ready for Rails 4 or not.
RoundPic : Online tool for making anti-aliased rounded corners (very Web 2.0!) for avatars and images
Site Valet : Web Tools for Quality, Accessibility, Standards Compliance.
