The company has prioritized its key product instead of developing social networking products or games. "We need to focus," Chai said. The firm has hired 20 physicians to gather data and research algorithms and related information.

Top 10 most popular instant messaging apps in the world

Videographic: the battle of the taxi apps

Chai's goal is to build a health and medical product by using menstrual cycle data so women can become healthier.

For instance, he has found that the average menstrual cycle in Chinese women has lengthened to 31 days instead of 28 days, which has been recorded for 2,500 years and still is widely recognized. "Women have evolved," he said. "It is a chance to redefine women through our data.

For example, their statistics can predict the next phase in a woman's reproductive life and even diagnose health risks, he said.

The potential market for female users of the application is massive. Wang Jian, an analyst from Analysys International, said female users on the mobile Internet have reached 250 million, and the number is growing.

Researching women has had an impact on Chai's views and actions towards the opposite sex. For example, female employees at Dayima, which takes half of the Internet company, have more benefits than their male colleagues. They get one paid day off during their period, meals and feminine hygiene products for free.

"I am more willing to listen to women and respect their needs on specific days with more understanding and respect," Chai said.