NOTE: This is a work on a partnership basis. So you will receive a certain percentage of the project profits instead of a one time payment for work.
If I were you, I'll probably search for somebody that already knows about me, like my friends. It's hard to find somebody from the internet who can work for 'free', and you can trust him.
Anyway, don't forget to use an escrow if you want to proceed with the developer deal, a lot of scammers in this forum, so better safe than sorry.