Apple's App store acheives 15 billion downloads mark with in just three years.

According to Apple, iPhone, iPad and iPod users had downloaded more than 15 billion applications in the past three years, and the released stats suggest the rate of downloads is sharply accelerating.

The latest figures from Apple show that customers have downloaded around 5 billion apps so far this year, considering the company said in January that it had just passed the 10 billion download mark.