In China, life is now governed by an official coronavirus health app on pretty much everyone’s smartphones. More important than a passport, more personal than a photo, the app decides who can go where. It can force people to cancel trips, retreat into isolation, or even seek hospital treatment.

Not having it really isn’t a viable option for most people in China. Without it, you can’t even get to work.

Once downloaded, the software operates like a traffic light: Green means “safe from COVID,” and allows the holder access to all buildings, including grocery stores and offices.

There’s no knowing when that green status might suddenly turn yellow. The app tracks everyone’s movements. It sends information on where they’ve been — and with whom — to China’s Big Brother-esque national health authority.

Just sitting in a coffee shop where, unbeknownst to you, a confirmed COVID-19 case dropped in for a latte, is enough to turn the app yellow.

If that happens, you’re added to a long list of people in line for possible mandatory isolation at home, or even quarantine at a government-run facility. No ifs, ands or buts.

It’s the perfect tool for limiting personal freedom, and while the government swears it’s only used to control the spread of the coronavirus, it’s open to abuse.

When a bank in Henan, in central China, ran into tech trouble recently, customers found they couldn’t withdraw their money online. Naturally, many headed to the bank to demand answers. According to state media, local authorities turned the angry customers’ health apps red to keep them outside.

After the story made headlines, and local authorities punished five officials on Wednesday for deliberately tampering with more than 1,000 citizens’ health codes.

That may sound like justice, but China’s track record on punishing corrupt officials isn’t good. Often, they disappear from public view for a while, but then resurface in different jobs.

The story also proves that China’s health app, now universally installed and accepted, can be repurposed to control citizens for other purposes.

So, how long will China’s leaders resist that temptation?