The audience for the HiddenLevers iPad app is a professional audience - investment advisors will be using the app in discussions with their clients. These are serious financial discussions, and the design should reflect that, while still maintaining an eye-catching look-and-feel.
Usability is key here - the scenario modeling screen as it exists today is quite complex. Try the link above, click around, and you'll see that it includes popup charts, light boxes, interactive sliders, and other UI elements. This functionality needs to be retained, but redesigned to work well and fit well on the iPad screen.