Apple's App Store has provided a breeding ground for tech-savvy entrepreneurs.  Inc. Magazine has a profile of 11-year-old Owen Vorhees, who studied up on the code for iPhone apps, and developed a math quiz that is now a top-15 seller in the paid, educational apps section of the App Store:

The premise of MathTime is simple: It takes the old-fashioned flash-card "mad minute" drill idea and adds a new-media twist. Players can practice addition, subtraction, multiplication, and division on the phone by quickly solving problems with two taps of the phone: one to show the problem, one to display the answer.

"I thought it would be cool," says the Hinsdale, Illinois, native. "It's really cool to make something work, to make a little money, to do something like this and see it up" on the App Store.

After Owen established the basic premise of the game, his 9-year-old brother, Finn, designed the mathematical symbols in Photoshop. Once the design was done, the boys pitched the program to Apple.

Read the Kid Entrepreneurs Build iPhone App here.