Sketching And Prototyping Tool: Pencil Project

Pencil Project is a free sketching & GUI prototyping tool which can be installed as a Firefox add-on or a standalone application.

You can paste a screenshot of a webpage and play with it’s built-in stencils like form elements & objects to sketch a design idea.

Free Sketching Tool

Pencil Project is very functional when you want to see how designs would look like with small updates like a putting a search-box and deciding where it will fit.

You can also install your stencils to this free sketching tool and improve it.

A killer feature would be importing webpages into this application directly. Hope it is the next step.