The cost of developing the Covid-19 tracer app is $6.425 million, according to the Ministry of Health.
A breakdown of the costs shows the app cost nearly $4.45m to develop, including project management and IT architecture.
Money spent supporting a spike in calls from the public and $350,000 for marketing accounted for a further $1.67m. Security costs were $305,000.
The breakdown of costs up to December 31, 2020, was provided by the ministry to the University of Auckland's Dr Andrew Chen, who put them up on Twitter.
"Overall, I think it's pretty good value for money as far as Govt IT goes, and is significantly cheaper than some of the costs seen in other jurisdictions," said Chen, a research fellow at Koi Tū, the Centre for Informed Futures.
The Herald first-revealed that Auckland app developer Rush Digital was the MoH's development partner for NZ Covid Tracer.
Recent data has revealed the number of daily scans on the tracer app has fallen from its peak of 2.5 million in September to around 500,000.
Director-general of health Dr Ashley Bloomfield has repeatedly warned that Kiwis could not afford to get complacent when it comes to using the app.
"We've seen how quickly the virus can spread," he said.
"We all have a responsibility to support contact tracing by keeping a record of our movements, either with the app or by another method such as a diary.
"When someone tests positive for Covid-19, the faster they can provide contact tracers with information about where they've been, the faster contact tracers can get ahead of the virus and break the chain of transmission."
This week Covid-19 Response Minister Chris Hipkins asked officials for advice on potential law changes that could address lingering privacy worries with the NZ Covid Tracer app.
New Zealand's app remains a critical tool for helping tracers quickly track down close contacts of people infected with Covid-19 - but at the same time, collects large amounts of personal information from users.
The Government has moved to allay surveillance worries by making the app "decentralised", leaving location data - like that loaded via QR codes - and interaction information, fed via Bluetooth tracing, on peoples' phones until it's needed for contact tracing.