Now I am writing an iPhone app which makes collage (an app that similar to pic collage/ papelook/ moldiv - you may want search them on app store to understand what is collage app). I need a designer who is responsible for whole user interface, stamps and backgrounds inside (you can use the app names above to estimate the work load of the tasks above). I expect the project can be finished within 2-3 months. I will give the app to testers for comments so the designer may need to modify their design for few times.
I want the designer not only draw according to my mind but also gives opinions in the whole app design and features. I have already come out with a collage style that testers love it so I have certain confidence that app will become popular. I want to give a proportion of income of the app to the designer as a reward and incentive.