I've got the ability to understand the requirements clearly and spend a lot of time in designing the architecture of the application, ensuring that I've considered all the use cases. More over, since you have mentioned that you need to add additional functionality, it might, most often that not, require refactoring, and I think I'm a good candidate for such scenario. I've spent days/months reading AOSP source and making subtle changes to match our requirements, especially because I'm into product development as against application development. And I love reading somebody else's code and understanding the design and control flow. As you have not completely put down the specifications for the project yet, I'm just gonna put the bare minimum bid for now.