As complacency takes a grip on Kiwis once again, the Government is hoping the roll-out of Bluetooth close contact tracking will turbo-boost the response in the event of a summer Covid-19 outbreak.
From tomorrow, Kiwis will be able to use the Covid Tracer app on their phones to record other devices they come into close proximity with.
It comes as the rate of QR scanning has plummeted once again, with only 8 per cent of app users actually scanning any codes in the past 24 hours on Monday.
"We need as many people as possible to use the app, so it's incredibly important that New Zealanders know they can trust the app with their personal information," Covid-19 Response Minister Chris Hipkins said.
The Bluetooth technology becomes far more valuable the more people use it, and is endorsed by the Privacy Commissioner.
"QR codes allow us to create a private record of the places we've been, while Bluetooth creates an anonymised record of the people we've been near.
"It allows app users to receive an alert if they have been near another app user who tests positive for Covid-19."
Public health experts have continued to urge the Government to make greater use of technology in its Covid response, especially as Kiwis have gone through varying levels of complacency in recent months.
There are currently 2.4 million registered users of the Covid Tracer app, 90 per cent of whom have phones compatible with Bluetooth tracing.
But Ministry of Health data shows the number of active users - people who used it in the past 24 hours - has plummeted from almost 1 million at the start of September to only 197,919 on Monday.
That means on Monday only 8 per cent of registered users were considered active users - though this reflects Sunday use, when fewer people are at work or using public transport.
Bluetooth tracing works by generating randomised "keys" and exchanging them with other nearby smartphones.
The keys don't contain any information about who you are or where you were, which means no personal or identifying information is exchanged.
The app will use the Apple/Google Exposure Notification Framework, but neither the Government, Apple or Google will be able to track movements.
When an app user tests positive, they can choose to alert other app users who may have been exposed to the virus. This involves uploading the "keys" that their phone has broadcast since they became infectious.
If your phone has one of the keys in the notification, you'll receive an alert along with advice on what you should do next to keep yourself and your whānau safe.
The Ministry of Health will not know you have received an alert unless you choose to get in touch for information and advice.
The ministry can still send out push alerts on the app about exposure events to people who have scanned QR codes in places visited by potentially infectious people.
The app will update automatically tomorrow, and can also be manually updated through the Apple App Store or the Google Play Store.
App users will be asked if they want to enable Bluetooth tracing when they next open the app. It is not mandatory to use it.
It also uses Bluetooth Low Energy, so the impact on phone battery should be minimal.
People who don't have smartphones might be able to use the Covid Card, though Hipkins didn't say when they might be available.
The card similarly uses Bluetooth to register other cards that it's in close proximity to.
The Government has been accused of dragging its feet on using technology to help the Covid response, with TradeMe founder Sam Morgan disbanding his Covid Card team in frustration months ago - even though the Government continues to investigate it.
The Covid Card was recently trialled in Rotorua and is still expected to be trialled at managed isolation and quarantine facilities.