Mobile analytics firm Flurry has published some new research into active iOS and Android devices, which makes interesting reading. It claims that by October 2012, there were 181m iOS and Android devices being used in the US, just ahead of the 167m in China, then a big drop to the UK (35m), Japan (28m) and South Korea (27m). “The US and China tower over the next group of top markets by at least five times. And while the U.S. has added a whopping 55 million net active devices since October 2011, China has added a dizzying 125 million, a figure that totals the sum of the UK, Japan and South Korea’s combined, current active user base,” notes Flurry, which reckons China will overtake the US by the end of Q1 2013. The company also breaks down the fastest-growing iOS and Android markets: China, Vietnam, Colombia, Chile, Ukraine, Venezuela, Turkey, Philippines, Egypt and Russia. It’s a useful reminder of the coming opportunity for digital music services in emerging markets.