We've seen plenty of remarkable kids -- the world is just bursting with them -- and Lim Ding Wen, a nine-year-old from Singapore is no exception. Like his father, Wen enjoys writing iPhone apps in his spare time. His application, called Doodle Kids, is a drawing application for children that he wrote for his two younger sisters, who enjoy drawing, and it's already been downloaded over 4,000 times (we just checked in the App Store and it does indeed appear to be quite popular) since its release on February 1st. Wen, who is fluent in six programming languages and enjoys reading books about -- you guessed it -- computer programming, is already hard at work on his next app, a game called "Invader Wars." We can't wait to see that one!