One framework, every device.

Bootstrap easily and efficiently scales your project with one code base, from phones to tablets to desktops.
http://getbootstrap.com/

Foundation

Getting started With Foundation is easy. Whether you are a master of Sass, building a new app, or making your existing site responsive.
http://foundation.zurb.com/

Wirefly

Wirefy was created as a tool to help web designers and developers create fast, manageable wireframes. It helps to speed up the journey between sketches and final deliverables.
getwirefy.com