Ask HN- Yo, where do all the app geniuses hang out

I have been working on a project for a while and I have a few meetings that will come up where I need to have some kind of prototype of an app that I will need developed.

I work with some great programmers, but they are in a very specific field and I am having a hard time finding someone I can hire to help with the app development, first the prototype and then full scale if/after I land the contracts. So, here it is... I am Looking for ideas on finding and hiring an app developer to do a basic app prototype for the Android OS...bonus points if you can do IOS too.

App is essentially 5 screens taking user through a transaction and would use potential client's graphics to minimize design work:

Screens: (1) Potential Client's Icon (2) Choose product (3) Choose product delivery method (4) Opt out of additional product features (5) Capture user selections in a 2d barcode capable of being scanned off a cellphone screen.

I think this is fairly straightforward, but am not an expert so I could be missing something.

I really need to know where to look to find the right person and greatly appreciate any pointers. If anyone has suggestions or is personally interested please contact me at projectmail7@gmail.com