The iTunes App chart has been topped by a game created by a teenager, knocking Angry Birds off the competitive top spot.

14-year-old Robert Nay’s ‘Bubble Ball’ was released on December 29th, 2010, and has already been downloaded more than three million times.

The teenager, from Utah, USA, taught himself the code to make his app from a library book and apparently designed the “physics puzzle game” himself with just a bit of help from his mum.

Bubble Ball has now topped the iTunes App chart, beating Facebook, Skype and the free version of Angry Birds.

Nay seems pretty surprised at his success, telling ABC News: “I think it’s pretty cool because I never thought my game would do that well.

“My friend’s dad suggested I try making an iPhone app and I thought, ‘Why not, that’d be pretty cool,’ so I checked out a book from the library.

“When I saw that it was number one for the free apps, I was astonished.”

Slightly galling for the teenage app wizard is the fact that it’s free so he won’t have to worry about being too young to drive a Ferrari.

However Nay says he now has a paid app in the pipeline.

Watch you back Bill Gates.

Check out Robert Nay’s Bubble Ball here.