The revelation that $21 million of taxpayers' money was effectively wasted through the Morrison government's adoption of the federal COVIDSafe app over two years ago should surprise no-one.

But why such a useless contrivance - described at its launch in April 2020 former PM by Scott Morrison as an "early ticket" out of lockdown - was allowed to linger on when it yielded such poor outcomes is an even greater indictment of how the previous Coalition government piled one blunder on another during the pandemic.

"Slip, slop and slap on the app" was the description offered by the Prime Minister in his attempt to promote it at the time.

But what a cash-eating debacle it turned out to be, not unlike the Lara Bingle-fronted "So where the bloody hell are you?" national tourism promotional campaign fiasco approved by Scott Morrison when our former PM was the head of Tourism Australia.

After $10 million was spent on development and hosting, a further $7 million was spent on advertising and marketing, $2.1 million went on upkeep and more than $2 million paid to staff, the app has now been decommissioned. US billionaire Jeff Bezos' Amazon Web Services trousered over $2.8 million for hosting.

Describing the COVIDSafe app as "wasteful and ineffective", the new Health Minister Mark Butler said it detected only two positive COVID-19 cases which were not found by manual contact tracers.

Fewer than 800 users consented to their data being added to the National COVIDSafe Data Store for contact tracing, which was an essential element to the whole concept.

The signals from government about the poor efficacy of the product were evident early on, with Commonwealth health officials reporting to Senate Estimates in 2021 that the app was not being used by public health officials and the public take-up was very slow.

One of the key points of public resistance was that the app used Bluetooth "handshake" technology, and that the person who installed it also had to register their details with the datastore.

That "handshake" was set up to record interactions with others so if the user had been around someone who had tested positive for COVID-19, they would be advised via SMS and could get tested. Which was fine for urban areas but not for regional areas, which led to another issue Telstra had to resolve.

The way in which the app functioned was complex - broadcasting an encrypted signal - and also caused an annoying power drain on people's phones. It also had early user installation issues and didn't work well with older iPhones.

There were no public consultations relating to privacy concerns about the app undertaken prior to its launch, which fed public distrust.

Research into main reasons why people didn't download the app revealed it was primary distrust of the government in handling personal data, the safety of having it running on your phone at all times, and its potential to be used as a tracking device.

A much more practical solution in the form of a QR check-in code to venues emerged not long after, was well understood by the public and widely adopted.

In April - before the election - a Senate inquiry found the app of "limited public value". But governments hate to admit mistakes, especially in pre-election mode.

So to quote Macquarie University research fellow Dr John Selby, the Morrison slip, slop and slap of the app proved to be little more than tanning lotion.