I used iRise to build this prototype in 2010. It was used in testing new grouping mechanisims to present to shoppers on Cars.com searching for new car inventory. iRise has consistently proved to be a capable tool in developing workflows consisting of multiple paths and edge cases to present to the user. That said, as I write this, it's 2013. I much prefer to do rapid prototyping work in html/css within the the constraints of well thought out frontend frameworks like Bootstrap.