Toutiao is best known for giving people their daily fix of clickbait. But China’s most popular news app is increasingly becoming useful for something else: Finding missing people.

Toutiao, which provides an endless feed of articles and videos tailored for each of its 120 million daily users, is also the country’s biggest finder of missing people. The South China Morning Post reports that the app helped locate more than 3,500 people last year, many of them victims of Alzheimer’s disease.

Toutiao’s missing persons feature helped locate more than 3,500 people last year

Here’s how it works: Friends and family fill out an online form, providing a photo and other details of a missing person. Toutiao then sends an alert to users of the app located within 6 miles of where the person was last seen.

In one recent case, a mentally ill man was separated from his brother at a railway station during the Lunar New Year travel rush. He was found three days later in a hospital, after a member of staff saw a missing person notice from Toutiao.

It’s not an uncommon feature. Elsewhere in the world, Facebook displays alerts on its news feed to help find missing children. The Google Person Finder, launched in 2010 following the devastating Haiti earthquake, helps people locate their loved ones after a natural disaster.

But this is a much-needed service in the world’s most populous country: About half a million elderly Chinese people go missing every year.