I've used online subcontractors many times in the past and have never had such a positive experience as I did on this project.
My developer produced a fully realized Android app in exactly the way I asked, even though several other bidders told me it would be impossible. He repeatedly iterated and improved the code based on my feedback and did a brief code review with me to explain the various details of the application. And he patiently explained elements of the Android platform to me that I should have understood before putting the project out to bid!
Again, I can't stress enough how positive I felt about this subcontracting experience. There was simply no nonsense whatsoever to getting the project done, and I will not consider any other developers for any future Android work I have.