This month, Chinese smartphone maker Xiaomi hit a milestone.

According to research firm Canalys, Xiaomi sold more smartphones in the first quarter of the year in China than Apple did. It's especially relevant considering Apple made its biggest push ever in China in January by finally selling the iPhone through China Mobile, the largest wireless carrier in the world with over 700 million subscribers.

It's the kind of growth that should have giants like Samsung, Apple, and Lenovo worried as the scrappy startup eats into their market shares in one of the most important battlegrounds for mobile computing.

Xiaomi is often called the "Apple of China," not just because its products look a lot like Apple's products, but because it elicits the same sort of fanboyism Apple does in Western countries. New Xiaomi devices often sell out within minutes online. The company's CEO, Lei Jun, is a Steve Jobs-like figure, right down to his uniform of black shirts and light blue jeans.