A smart way to make ends meet while developing your own apps

I was in the concept stage of a very similar project, when I came across this project. It's precisely what I was envisioning. I think the model of creating a very broad iOS/Mobile code framework that would allow you to sell/license to specific markets. Creating customized builds of the app for various clients.

Anyone else working on something similar? I have 2 or 3 other big markets I think this model would work using this model.