This seems like a hard one... The thing that gets me about your post is that your friend "is not interested in being an entrepreneur". That's what this website is about! Lots of people have great ideas. Shit, I have had dozens of ideas that other people have taken and made a good fortune marketing and using. Do you know how much money I have made off their ideas? $0.00! Diddley shit. That's because ideas don't sell. If you must, I would highly recommend finding someway to 'prototype' the idea (like making the product first yourself), then taking it to some app developers and seeing if they like it. But with apps, why not just produce it yourself?