Where did things go wrong with Canada's COVID Alert app?

In the summer of 2020, Prime Minister Justin Trudeau touted the new COVID Alert notification app as a tech-forward tool to help trace and slow the spread of the coronavirus.

Nearly two years later, uptake has plateaued, and questions remain about whether the roughly $21 million spent to develop and promote the app was worth it.

"I don't think the COVID Alert app made much of a difference in our fight against COVID," Peter Loewen, director of the Munk School of Global Affairs and Public Policy at the University of Toronto, told CBC's Cost of Living.

"That doesn't mean that it was a waste of money, necessarily. We didn't even spend enough money to really try."

The COVID Alert app launched in July 2020 for Apple and Android devices. The app uses Bluetooth signals to exchange random codes with nearby phones that also have the app installed.

Users are alerted if they've spent at least 15 minutes near another user who has tested positive for COVID-19.

Health Canada told Cost of Living that the app has sent more than 371,875 alert notifications as of Jan. 31.

But it doesn't track users' names, addresses or location data, nor does it collect any data on whether a user actually follows up at a testing centre.

Without that key information, "it's simply impossible to say that the app did anything of significance," said Jason Millar, Canada Research Chair in the Ethical Engineering of Robotics and Artificial Intelligence at the University of Ottawa.

"You should be extremely skeptical of anyone who claims they can measure the app's success in preventing cases or saving lives.... There is no data that I've seen to support the claim that it did anything of the sort."

According to Health Canada, the app "was designed to provide [a] high level of privacy protection" and shouldn't be considered a replacement or supplement for more detailed contact tracing.

Health Canada told Cost of Living that the app has been downloaded about 6.86 million times. If each download translates into one unique user, that's about 18 per cent of the country's 38 million people.

Each province and territory was required to opt into the program in order for people to use the app. It wasn't adopted by Alberta, British Columbia, Nunavut or Yukon.

Loewen says the app would need to be downloaded by at least 60 per cent — and preferably even 70 or 80 per cent — of Canadians to be truly useful. But he says it's incredibly rare for a single app to get that kind of widespread usage.