One of the most talked-about new apps in China opens with a blunt prompt that feels equal parts joke and warning: “Are you dead?”

The app, designed as a digital safety check-in, has gone viral among young people living alone in China’s largest cities. Users assign an emergency contact who is notified if they fail to confirm their wellbeing for several days. In a country where urbanization, long working hours, and changing family patterns are reshaping daily life, the app’s sudden popularity has struck a nerve.

Launched last May as a free download and later priced at 8 yuan (about $1.14), the app recently became the most downloaded paid app on China’s Apple App Store. Shortly after its surge in attention, it disappeared from the Chinese App Store for reasons that remain unclear.

Marketed as a “personal safety assistant,” the app targets people living independently, from young professionals and students studying far from home to anyone choosing a solo lifestyle.

Its co-founder, Ian Guo, told NBC News that the app’s success exceeded all expectations. Built for less than $150, it is now estimated to be worth around $15 million. Guo and his two co-founders are part of China’s so-called post-95 generation, and the idea came directly from online conversations.

“We saw people saying this was something they needed,” Guo said. “We asked ourselves if we could quickly build a product that actually gives people more security.”

Having lived alone in Shenzhen for years, Guo said he understands the constant mix of loneliness and unease that can come with solo urban life.

While the concept may sound morbid, its resonance reflects deeper demographic shifts. By 2030, China could have around 200 million one-person households, according to the state-backed Global Times, citing real estate research institutions.

The app’s original Mandarin name, “Si Le Ma,” is a wordplay on “E Le Ma,” a popular food delivery app whose name translates as “Are you hungry?” Some users felt the reference to death was too dark. The app has since been renamed Demumu, a change Guo described as “cuter.”

To many young users, the name still feels awkward. “Are You Dead? sounds like a joke,” said Lisa Li, a 23-year-old English teacher. “But Are You Alive? sounds like you’re coming back from the dead, which is even stranger.”

Li said she found the app amusing but impractical. “If I forgot to check in, I’d worry people would actually think something happened to me,” she said. She believes many downloads were driven by curiosity rather than real need.

Still, some concerns are deeply felt. A series of widely reported cases involving young professionals, particularly in the tech sector, dying suddenly after periods of extreme overwork has heightened anxiety about being alone and unseen.

For others, the app arrived during vulnerable moments. Cui Xiyue, a 23-year-old exhibition planner in Beijing, downloaded it while struggling with depression. “Back then, just getting through one day was hard,” she said. She checked in daily at first, but eventually stopped. “I don’t really need it anymore. I’ve moved past those darker thoughts.”

Loneliness has long been associated with China’s aging population, especially as younger family members move from rural areas to cities. More than one-fifth of the country’s population is now over 60.

But isolation is increasingly affecting younger generations too. Rising living costs, intense job competition, and declining interest in marriage and children have left many young adults living alone for longer periods.

Yuying Tong, a sociology professor at the Chinese University of Hong Kong and co-director of its Centre for Chinese Family Studies, said the app could be genuinely useful, even if its tone is ironic.

“There is sarcasm in how young people talk about it,” she said. “But it also invites reflection on what it means to live alone.”

Online reactions have been mixed. On Weibo, some questioned the app’s practicality. “If I get busy and forget to check in, wouldn’t I ‘die’ every other day?” one commenter asked.

Others pushed back against the idea of another obligation. “You clock in at school, clock in at work, and now you have to clock in to prove you’re not dead,” one user wrote. “A lifetime of clocking in.”

Tong believes loneliness may be less severe for young people than for older generations because they are more adaptable online and offline. She pointed to a recent example on Douyin, where thousands of strangers traveled to a village near Chongqing to help a young woman and her father prepare pigs for a traditional banquet after she posted a call for help.

“Young people can find ways to overcome loneliness,” Tong said. “If they are truly willing to.”