Tang Yan calls his Chinese social app Momo a “combination of Snapchat and Tinder.” And just like them, he’s pushing the limits in his country. Momo is huge in China, ranking as one of the top social apps with 150 million registered users (52 million active monthly) after being released in 2011. It’s been called “hormone-filled” by state media, but Tang says Momo wasn’t built for dating or one-night affairs. (Mo is part of a Chinese word meaning stranger.) Rather, the location-based system, which allows users to find new friends around them, is targeted at China’s big city arrivals who want to find a new social circle. Of course, they many also want a partner: Of the 900 million messages sent each day, 600 million are between two people and five percent are about hooking up. (Momo also has tens of thousands of groups for dating, sports, and entertainment.) Tang, has already set up a subsidiary in San Francisco to think about U.S. expansion.