Yes, I'm also curious. One iphone app generates 40k of income a month @ $.99 per unit? Interesting. I'm surprised more people aren't discussing that, rather than the "omfg you travel" and blar blar blar...
Totally agree...I'm pretty floored that this art app is generating $40k a month. Would not have guessed that. Congrats man. That's newsworthy.
He describes his business in a past HN post: "I sell apps on the app store. A lot of small cheap apps."