[Analytics] Shein: The mysterious Chinese fashion app that’s as popular as Amazon Every night before bed, Anushka Sachan whips out her phone to log into an app. “It kind of becomes a habit,” said the 20-year-old Hong Kong University student. “Before sleeping, I’m just like, ‘Okay, check in.'” Michelle Toh specially for the CNN Business . The platform Sachan is using belongs to a Chinese brand called Shein — pronounced “She In” — which has rapidly attracted a global army of teen fans on TikTok. The company is a mysterious online shopping upstart that has made headlines recently for surpassing…