An indie app with only one function is currently all the rage in China. It’s called si le ma (死了吗), which translates literally to “Are You Dead Yet.” The app asks users to tap a button once every day, and if they fail to do so for two consecutive days, it automatically sends an email to a designated emergency contact, urging them to check on the user in person.

Guo, one of the three Gen-Z developers behind Are You Dead Yet, says he has been building social and entertainment apps for a few years. But he wanted to pivot to something more fundamental. “When I looked at Maslow’s hierarchy of needs, I saw that safety needs are deeper and apply to a much broader group of people. That felt like a good direction,” Guo told WIRED in an exclusive interview. (He asked to be identified only by his last name, for privacy reasons.)

The app’s practical functionality and the dark humor its name evokes have struck a chord with young people in China, who swarmed to download it over the past week. At the time of publication, Are You Dead Yet was the number one paid app in the Chinese version of Apple’s App Store. It is also climbing the rankings in overseas app store charts, even though Guo says he hasn’t spent a dime on paid advertising. “We don’t have that kind of money,” he says.

Guo tells WIRED that the team has been contacted by more than 60 investors since Are You Dead Yet blew up on social media, and they are in active conversations about fundraising. He claims that some investors have offered millions of Chinese yuan—hundreds of thousands of US dollars—for a stake in its parent company, Moonscape Technologies, which has released just a handful of apps. The team expects to announce the results of the fundraising talks in a few weeks. “We knew there would be some traction, but the scale of this completely exceeded our expectations,” Guo says.

Guo and his colleagues initially charged users a one-time payment of 1 RMB (14 cents) to use the app; amid the heightened attention this week, they raised the price to 8 RMB ($1.15), still a minimal amount considering there’s no subscription required. While Guo declined to disclose how much money the app has made or how many active users it has, he says the money they have earned so far will go toward developing the platform for the long term.

Are You Dead Yet has caught on particularly among people who live alone. The average size of a Chinese family has shrunk dramatically over the past few decades. According to a 2020 national census, 25.4 percent of households consisted of just one person, up from 14.5 percent a decade earlier. While elderly people remain the most likely to live alone, there is a growing cohort of younger people living a solo lifestyle, and Chinese businesses are increasingly catering to this demographic by offering digital or physical companionship services.

On Tuesday, the developers announced on Chinese social media that Are You Dead Yet would officially change its name to Demumu in order to better serve the global market. That name, which was also used for the app’s overseas version previously, was inspired by another Chinese business success. Guo says Demumu is a combination of the word “death” and the naming pattern of Labubu, the Chinese plushie monster that went viral globally last year.

Fans of the app are not thrilled. Even before the announcement they had been asking the developers not to change the blunt name, which was half the appeal. On Weibo, a Chinese social platform, the most liked comment under the name-change announcement reads, “Baby, your previous name was the reason you went viral.”

The first version of Are You Dead Yet launched on the App Store in June 2025 and was free to use. The interface is extremely simple, with a blank background and a gigantic green button for checking in. When users open the app for the first time, they enter their name and an emergency contact email. Moving forward, they simply tap the big green button each day to let the app know they are still alive. The app only took around $200 to make, according to Guo, and the name was a playful twist on E Le Me (“Are You Hungry Yet”), a popular food delivery app in China acquired by Alibaba in 2018 for $9.5 billion.

Data from Sensor Tower, a market intelligence firm, shows that Are You Dead Yet initially received little attention when it launched. It started growing in popularity in late December and officially became the most downloaded paid app in China on January 9. Guo says he believes the app gained its first traffic boost when it was picked up by an influencer on RedNote, a popular Chinese social platform.

Guo says the team plans to soon incorporate artificial intelligence into the platform, allowing it to more actively monitor a person’s safety. He didn’t mention any specific features but described the team’s vision as “essentially like having an AI safety companion installed on everyone’s phone, one that can offer all kinds of help when you need it.”