China said on Monday it would retire an app used to track Covid-19 contacts, a milestone in the country’s rapid turn away from its zero-tolerance coronavirus strategy.

The state-run “Communications Itinerary Card”, which tracks whether someone has been to a high-risk area based on their phone signal, will go offline at 12 am Tuesday, according to an official WeChat post, after more than two years in operation.

The “Itinerary Card” was a central part of China’s zero-Covid policy, with millions of people required to key in their phone numbers to produce its signature green arrow in order to travel between provinces or enter events.

The decision comes just days after China announced an end to large-scale lockdowns, mandatory quarantine in central facilities, and a broad relaxation of testing measures, effectively throwing in the towel on its zero-Covid strategy.

Official reported cases in the country have dropped sharply from all-time highs last month, but top Chinese health expert Zhong Nanshan warned in state media on Sunday that the prevailing Omicron variant was “spreading rapidly” through the country.

First rolled out in 2020 with a four-tier system that assigned different colours depending on users’ predicted level of Covid exposure, the Itinerary Card was tweaked multiple times before a final change this year shortened the tracking period from 14 to seven days.

It is only one of a panoply of tracking apps that have governed everyday life in China throughout the pandemic, with most people using local “health codes” run by their city or province to enter shops and offices.

But social media users nevertheless hailed the Itinerary Card’s retirement, noting the symbolism of Beijing shutting down its main tracking app.

Many posted screenshots of their “last” logins.

“Bye bye, this announces the end of an era, and also welcomes a brand new one,” one person wrote on the Twitter-like Weibo platform.

“Goodbye itinerary card, concerts here I come,” wrote another.

Others asked what would become of the mountains of data collected by the app.

“The Itinerary Card and other similar products mean vast amounts of personal information and private data,” wrote one Weibo user. “I hope there will be mechanisms and measures to log out and delete this.”