The number of developers in China contributing to iOS and the App Store has grown by 70 percent over the past year to more than half a million, Apple revealed on its fiscal Q3 earnings conference call on Tuesday. That’s almost twice as many as the 275,000 iOS developers registered with Apple in the US.

While Apple has been on a tear in China in recent years, the company’s revenue in the region during the June quarter was down a surprising 43 percent sequentially and 14 percent year-over-year. Apple CEO Tim Cook noted on the call that Hong Kong had contributed to the drag, as sell-through in mainland China was up 5 percent year-over-year after accounting for inventory changes. He also said the current state of China’s economy has posed difficulties for Apple and its competitors.

Cook did, however, try to put into perspective that Q3 revenue of $4.6 billion was still a strong showing compared to a few years ago, when it was just in the hundreds of millions.

Looking ahead, Apple plans to double the number of retail stores it has in Greater China over the next two years.

See also: Apple’s Greater China revenue climbs 8% YoY to $8.2B in Q2 2013, comprising 18.8% of global total