What I think is interesting is, they go through the normal thoughts of becoming rich from the app. store, even though their idea is very niche and overly compli

What I think is interesting is, they go through the normal thoughts of becoming rich from the app. store, even though their idea is very niche and overly complicated [solving differential equations by taking pictures of them]. Penny's simple idea would have mass appeal and probably do quite well [taking pictures of shoes and telling you where they can be bought]