Cult following

Bullet, developed by Beijing Kuairu Technology, says it amassed 5 million registered users within 10 days of its launch. It is backed by Smartisan Technology, a niche smartphone maker founded by English-teacher-turned-entrepreneur Luo Yonghao.

Kuairu said it has a team of just 36 people with an average age of 27, and raised 150 million yuan ($22 million) from venture capital within seven days of the app's launch.

The company declined to give details and turned down a request for an interview.

Company registration records show Kuairu was registered in May with capital of 100,000 yuan.

Zhang Ji and Hao Xijie, both former Smartisan managers, are listed as its two directors, while Wang Li, chief operating officer of Chinese dating app Momo Inc was listed as the sole owner as of May 9.

Momo said Wang is an investor in Bullet but did not hold any position at Beijing Kuairu.

According to Chinese corporate database Tianyancha, Smartisan and two local venture capital firms, Chengwei Capital and Gaorong Capital, invested in August.

Chengwei and Gaorong did not immediately respond to a request for comment.