I have been through this a lot with a music/art interactive platform I've been working on for the past year and a half or so. My gut take on this is that programmers have the same problem musicians have; although they may be in demand, they overestimate their ability to evaluate potential enterprises. (great players have about as much trouble evaluating whether a band is worth joining as A&R people did picking winner…
Your biggest problem is probably that Objective C developers are in extremely high demand. They can make a lot of money, or if they have an interest in start-ups the barrier for entry is so low to get in the app store that they probably don't see a need to partner. Everyone has a dozen ideas for cool apps. It sounds like you have a pretty compelling pitch, but you are pitching to a very small market with tons of comp…
Thanks for your well wishes!