You'll go very far with that one. I haven't clicked the link yet but this is definitely the way forward. Don't sell for less than a billion and please do a version for Android that can be used offline using Cordova.
Thank you -- currently, my main focus is for prototyping web application, as there are already a few big players in the mobile app prototyping space and I would like to learn more about how users prototype applications before venturing into that space -- but it's definitely something I'll consider in the future and thanks for your interest!