CogTool

CogTool is a general purpose UI prototyping tool with a difference - it automatically evaluates your design with a predictive human performance model (a "cognitive crash dummy").
To use Cogtool today, simply create a storyboard of your design idea with sketches, images or on a canvas with CogTool's widgets, demonstrate tasks on that storyboard, then press a button to produce a valid cognitive model predicting how long it will take a skilled user to complete those tasks.

CogTool can be used today to baseline your current interface, or compare competitors' interfaces, and predict how much better your new designs will be.