The number of Chinese application developers for Apple Inc's iOS mobile platform has surged by more than eight times over the past three years, but analysts warned that being too dependent on a single system is risky.

Apple CEO Tim Cook said on Monday that Apple has more than 6 million registered developers globally, with 1.5 million added in just the last year. He made the remarks during the company's annual World Developers conference, which is being held in San Francisco from June 10 to 14.

"We have now paid developers $10 billion, and the momentum is incredible. We paid $5 billion of that just in the last year," Cook said.