There are people who make some serious bread from the App Store. Matt Rix, the creator of the wildly popular iPhone game Trainyard, is one of them. Here's how he did it, starting with his sketchbook.
Trainyard may be a simple iPhone game, but it's one of my latest addictions. Folks who are nuts about logic and puzzle games—as well as those who adore Flight Control or ColorBind—are very likely to love it, too.