An initial version of the government's new coronavirus contact tracing app has been formally launched.

Kiwis who download the NZ COVID Tracer app can create a digital diary of the places they visit by scanning QR codes displayed at the entrances to business premises, other organisations and public buildings.

The government noted that the app does not replace the need for businesses to keep records as well.

People can choose to also register their contact information through the app so the National Close Contact Service (NCCS) can get in touch if it needs to.

"That (the contact details) is the information, and the only information, that is then held by the Ministry of Health, and by the ministry only. It is only used if needed for contract tracing,” explained Dr Ashley Bloomfield, Director-General of Health.

Bloomfield had previously explained that any information about an app user's movements that the user decided to record with the app would be stored securely on the user's phone and deleted automatically after 31 days.

"It’s your choice whether you share any of this information with contact tracers, and any information you do share will be used only for public health purposes and never for enforcement.”

To open at Level 2, businesses must keep contact tracing records. This led to a flurry of apps being launched, or shoppers having to fill out physical forms. The government app is just the first version of what is planned, it would be updated as new features were developed. 

“One of our key public health responses to COVID-19 is to identify, trace and isolate cases and close contacts to prevent further spread.  This app will help us do that.  The more Kiwis that download and use it the better placed we are to act promptly to keep other New Zealanders safe," Bloomfield said.

The Ministry of Health said it had consulted the Privacy Commissioner to ensure NZ COVID Tracer protected users' privacy. The app had also been through independent security testing.

An update planned for early June will enable users to electronically transmit their digital diary to the NCCS, enable a user to receive a notification if they had been at the same location at the same time as someone who had COVID-19, and enable the user to carry out a daily health check-in if they were in isolation or quarantine.

The app is an interim solution, and other technological contact tracing solutions are being developed, similar to what has been used overseas.

Singapore has been using a bluetooth app called TraceTogether, which logs contacts who come within two metres of each other, and Australia is using a similar app called Covidsafe.