Sounds to me like they're startup enthusiasts, and want eat.ly to get bigger and better without sacrificing the stability they have right now, with their full-time jobs.
In other comments, people are saying the iPhone app is important. I think they already know this, and what would be more interesting to them is any shortcuts they could take to build their iPhone app.
I think they ought to find an iPhone developer who has developed an app similar to what would be needed for eat.ly, and is in a similar position where they are enthusiastic about startups but not doing it full-time.
As far as shortcuts I'd recommend doing the "app" as a jqtouch view of their rails? app. That should work for the vast majority of users and avoid the whole outlay for the app store. They could also look at phonegap. It's far better to figure out down the line that you need a full blown app than to figure out that your app could have been done in HTML. iPhone is a pretty big learning curve.
In other comments, people are saying the iPhone app is important. I think they already know this, and what would be more interesting to them is any shortcuts they could take to build their iPhone app.
I think they ought to find an iPhone developer who has developed an app similar to what would be needed for eat.ly, and is in a similar position where they are enthusiastic about startups but not doing it full-time.