A screenshot from Lim Thye Chean's website shows some of the code for his son's Doodle Kids program. (Lim Thye Chean's website)

A nine-year-old boy has created an application for the Apple iPhone that allows users to "fingerpaint" on the phone's touch-screen.

Tracing your finger over the screen while the program Doodle Kids is running allows you to create multi-coloured shapes. The screen can be cleared by shaking the iPhone.

Fourth grader Lim Ding Wen wrote Doodle Kids for his younger sisters, who are three and five, his father Lim Thye Chean said.

"It is designed and written completely by himself," the elder Lim wrote on his website. He bills his son as "probably one of the [world's] youngest iPhone developers," and said the boy has been programming since he was seven.

Lim Ding Wen, 9, wrote the program for his younger sisters, aged three and five. (Courtesy of Lim Thye Chean)

Doodle Kids has been available for free download since Jan. 19.

As of Friday, it had been downloaded 12,000 times, and 6,000 of those had just been in the past day after media reports about the program were published on the internet, the elder Lim told CBCNews.ca in an email.

The original version of Doodle Kids was written in Pascal — a computer language — for the Apple IIGS computer and adapted for the iPhone.

Ding Wen's latest programming project is Invader War, a space game written in Orca/Pascal for Apple IIGS. His father's website said it is currently in development as an iPhone application also and will be available for download at the App Store when it is finished.

The elder Lim, who is the chief technology officer of a technology company in Singapore, said he teaches children to program in his spare time.