I have a business partner who wants to do a deal where I will get a percentage of the profits from app sales. I like the deal and want to do it. In our business agreement I want to put some language that defines what happens as the project moves forward - for example, what if he wants app updates that I don't think are necessary? What if he wants to work with a different developer in the future, but wants to use the code that I developed? 
Creating Deal for Percentage of App Sales
contract