When Chen Xiaozhe downloaded the smartphone application Momo, his intentions were clear. "My principal motive was to try to have sex with a wide variety of girls," said Chen, 27, who runs an online shop.

To attract potential dates, Chen updates his profile with photos of his BMW or selfies in posh restaurants. It is easier to meet women online, according to Chen, because in person they tend to be shy, if money-oriented. "If I can manage to satisfy their material desires, generally they are willing to sleep with me," he said.

In a country with 700 million smartphone and tablet users, the mobile sector has become a hotbed of innovative startups. One recent success is Momo, a social networking app created in 2011 that has experienced growth akin to that of products by China's technology giants, such as Tencent's WeChat. In August 2012, Momo had 10 million users; by February this year there were 100 million, or double the number on New York-based networking site Foursquare.

Momo is free to download and uses location to connect users through one-to-one or group chats. It offers various services such as online gaming and local interest forums. But its reputation, much like that of Tinder, is for facilitating one-night stands.

Zhang Chenyi, a 23-year-old administrator with dyed chestnut hair, a cropped T-shirt and fake eyelashes, gets propositioned on Momo 10 times a day. "I want to make as many friends as possible," she said, revealing a typical divide in the motives of male and female users. "If I communicate with a guy on Momo for around one month, and feel that I understand him, I would consider going for dinner."

China's rapid modernisation has given rise to a young generation whose attitudes towards sex and relationships are starkly different from that of their parents and grandparents. Premarital sex is now common, but puritanical attitudes endure.

While Momo's salacious reputation forms part of its appeal, it also causes problems. Momo was the only app chastised during the National Office Against Pornographic and Illegal Publication's latest crackdown on online porn. A report in Xinhua, the state-owned news agency, described it as "hormone-filled" and a tool for sex workers to lure customers.

Lately, Momo has attempted to distance itself from its "hook-up" association through marketing campaigns. "It could be controversial for Momo to be associated with corrupting young people," said Steven Millward, chief editor of Tech in Asia. "We've seen recently that authorities are worried about people being corrupted by US television shows. There's an attempt to protect the moral fibre."

For users such as Chen, Momo is simply a way to meet like-minded people. "Face-to-face we pretend to be pure and clean, but we all have dirty thoughts," he said. "I am still young, I wish to experience the best of life and in all honesty I enjoy having sex with different girls. Momo makes it happen."

Some names have been changed