Demo : http://getclank.com/demos/

Clank is an open source HTML and CSS framework for prototyping native mobile and tablet apps. It uses modern CSS techniques, with Sass and Compass, and it’s component based so you can pick and choose what you need.

Chanko — Safe and rapid Rails app prototyping

Chanko offers a simple framework for rapidly and safely prototyping features in a production Rails app. You can expose those changes and new features to specific segments of your user base, and if Chanko produces any errors, it’ll be automatically removed without impacting your site.