For the first time ever, China has surpassed the US in iOS and Android device activations, taking the top spot globally. App analytics company Flurry reports that last month, Chinese users on the two platforms activated more new devices than people in any other country; in March, they're estimated to make up 24 percent of all new activations compared to 21 percent in the US. That's a huge leap from the beginning of 2011, when China made up only 8 percent and the US 28 percent.

China is still second place in total install base: Flurry estimates that there are twice as many iOS and Android phones and tablets in the US. With China's rapid growth and the official release of the iPhone on more Chinese networks, though, it's unlikely to stay that way for long. Even if most users stick with low-cost feature phones, China's population is big enough that a small percentage is a huge raw number, and the country has nearly a billion total mobile subscribers. China also saw a 1,100 percent growth in use of mobile apps over the past year, about twice as high as the growth rate for any other country. These numbers aren't directly from manufacturers or developers, and they don't include platforms like Windows Phone or BlackBerry, but it's still a solid indication of where smartphone and tablet adoption is going.