While most children his age sketch on paper with crayons, nine-year old Lim Ding Wen from Singapore, has a very different canvas — his iPhone.

Lim, who is in fourth grade, writes applications for Apple's popular iPhone. His latest, a painting program called Doodle Kids, has been downloaded over 4,000 times from Apple's iTunes store in two weeks, the New Paper reported on Thursday.

The program lets iPhone users draw with their fingers by touching the iPhone's touchscreen and then clear the screen by shaking the phone.

"I wrote the program for my younger sisters, who like to draw," Lim said. His sisters are aged 3 and 5. Lim, who is fluent in six programing languages, started using the computer at the age of 2. He has since completed about 20 programing projects.

Lim isn’t the only young entrepreneur making money online with iPhone applications, last month we reported on a bunch of 22-year olds who were earning $100,000s online selling their iPhone application online. Perhaps one day we will see one of these programmers join our Rich List through their success of programming iPhone applications!