I trust many Hongkongers have heard about the LeaveHomeSafe coronavirus tracing app - but how many have actually downloaded it?

I would think not too many. While it must be stressed that this is just a guess, the only authority to give the facts and figures is the government's top man in charge of innovation and technology, Alfred Sit Wing-hang.

Similar tracing apps have been in use for a while in other parts of the world, from Singapore to Britain.

Hong Kong was a little late on this, having waited until August to invite tenders for the project.

It was only early this month that the SAR came up with an app of its own to locate close contacts of those infected.

The less-than-enthusiastic response to the app's launch may has been due to either a failure of the administration to properly publicize it or people's concerns about possible privacy leaks.

But underlying the unimpressive launch is the lack of people's trust in their government - and only when it manages to regain their confidence will the people be willing to step forward and accept the app.

Tracing apps were never an issue when introduced in Singapore or Britain. Were their nationals less concerned about their personal privacy than their Hong Kong counterparts? I don't think so.

But the Singaporeans and Brits have greater trust in their governments - and this is a confidence barrier that Chief Executive Carrie Lam Cheng Yuet-ngor must overcome.

The Singaporean government launched its app in March and nearly three million Singaporeans have downloaded it so far.

For a tiny state with a population of just over 5.8 million, the project has proved highly successful. The statistics mean that almost all adults and teenagers with smartphones have downloaded the app.

To assist the elderly and younger ones who struggle with technology, the Lion City has given them a tracing gadget that interacts with their surroundings.

By all measures, the tracing system used there is far more sophisticated than the LeaveHomeSafe version we are using here - in fact, it is nowhere near state of the art.

It is, in fact, a QR code system similar to that being used in Britain for some months by which customers are required to use their smartphones to scan a QR code to check in when visiting restaurants or other designated premises.

The British QR code system is not foolproof and customers unwilling to comply are free to just walk away from the premises.

Its effectiveness also depends on how strict operators of these venues are willing to enforce compliance - some staff are strict about insisting on customers using the app while others are more lax.

How successful will the SAR's tracing app turn out to be? It all boils down to how far the public is willing to place their trust - in the scheme as well as those administering it.

Public health concerns more than privacy