The Government's coronavirus tracing app has been released, and its uptake will play a large part in helping ease restrictions.

The COVIDSafe app will allow authorities to quickly notify people if they have been in contact with someone who has been infected with coronavirus.

The voluntary app can be downloaded now and people have been able to register their details — even using a fake name if they want — from 6:00pm AEST on Sunday.

"The COVIDSafe app is about assisting, finding those cases which may be undiagnosed in the community, helping people get early treatment, helping people have early diagnosis and to ensure that our doctors and nurses, our health workers, our families and friends are protected and that will save lives and protect lives," Health Minister Greg Hunt said as he launched the app.

Chief Medical Officer Professor Brendan Murphy said he would be using the app.

"No Australian should have any concerns about downloading this app," he said.

"It is only for one purpose, to help contact tracing. If someone becomes positive, that is all it is for and all that it will be used for."

There are questions around what installing a data-collection app means for privacy.

Wondering if you should use the app, what is involved, what access you may have to give the app and what data is taken from your phone? Here's the latest that we know.

What does the app do?

The app will speed up the contact-tracing process by several crucial days, Professor Murphy said.

It won't be coded to collect location information as it functions simply like a proximity detector.

When you register with the app, it will collect a name, your mobile phone number, age range and post code. It will also generate an encrypted code unique to you.

When you're close to someone else with the app, their app will record your encrypted reference code, as well as the date and time, your proximity and the duration of contact.

The information shared by the app will be stored on phones for 21 days and deleted after 22 days.

That's long enough to allow for a 14-day incubation period and the time it takes to confirm a positive coronavirus diagnosis.

If anyone using the app tests positive to COVID-19, they would be asked to download their encrypted contact log and send it to the Government, which will store it in a central server in Australia.

Only state and territory health authorities will then be able to access the cloud, decrypt the data and contact those who were in close proximity to the COVID-positive person.

"If you become infected with coronavirus, the app will assist health officials to notify people you've been in close contact with so they can self-isolate and get tested," the Government said on its COVIDSafe website.

"This will speed up current manual processes and make it quicker to stop the spread of the virus, particularly if restrictions are eased."

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Why should I download it?

Data collected from the COVIDSafe app cannot be used for any kind of law enforcement. ( ABC News: Keane Bourke )

This increased ability to follow up on potential exposure to infected people could help authorities control or respond to outbreaks, and is why the widespread use of the app has been framed as critical to easing restrictions.

"Without the assistance of technology, finding people who may have been exposed to the virus relies on people being able to recall who they have been around and knowing the details of every individual they have been in close contact with," the COVIDSafe website said.

"In many cases, we don't know the names and contact details of those we've been in close contact with (for example, at the supermarket).

"The app uses technology to make this process faster and more accurate. It has been developed to ensure your information and privacy is strictly protected."

The Government has explicitly said using the app will help save lives and has repeatedly linked its proliferation to any plans to ease restrictions.

It has also said it would not use any data for other purposes.

"The app cannot be used to enforce quarantine or isolation restrictions or any other laws," the COVIDSafe website said.

Mr Hunt said unauthorised use of the data was a criminal offence.

"The data has to be kept on an Australian server. It cannot leave the country. It cannot be accessed by anybody other than a state public health official," he said.

"It cannot be used for any purpose other than the provision of the data for the purposes of finding people with whom you have been in close contact and it is punishable by jail if there is a breach of that.

"There is no geolocation. There is no Commonwealth access."

Data cannot be taken from phones that do not have the app installed and downloading it is not mandatory.

When the app is deleted from a phone, all contact information is also removed.

A pseudonym can also be used when registering details on the app.

What does the app look like?

The COVIDSafe app can be installed onto any Android or Apple mobile with an Australian number and Bluetooth.

"To be effective, users should have the app running in the background of their phone whenever they are coming into contact with people," The COVIDSafe website said.

"Users of the app will receive daily notifications to ensure the app is running."

If you want to see what it looks like but aren't certain you want to put it on your phone, check out the images below.

This is what the app looks like on an Android phone when opened for the first time.

A screenshot of the COVIDSafe app as seen on a mobile phone running Android software. ( ABC News: Michael Collett )

A screenshot of the COVIDSafe app as seen on a mobile phone running Android software. ( ABC News: Michael Collett )

A screenshot of the COVIDSafe app as seen on a mobile phone running Android software. ( ABC News: Michael Collett )

A screenshot of the COVIDSafe app as seen on a mobile phone running Android software. ( Supplied )

What access does it want?

To work, the app needs to be left open with Bluetooth and push notifications turned on.

COVIDSafe does not need to be connected to the internet continuously but will need to occasionally download temporary IDs and will use less than 1MB of data each day doing so.

Android users will have to give COVIDSafe location permissions, but this is only due to requirements Bluetooth has for running on those devices.

"COVIDSafe app does not collect or use location data on Android," the COVIDSafe website said.

While people may worry the extra load on their phone will drain its battery faster, tests have shown power consumption only increases slightly with the app running so you may not even notice an effect.

Using Bluetooth with COVIDSafe won't impact other devices that use the technology, like wireless audio equipment or smart watches.

Any data relating to contract-tracing cases involving a person with coronavirus will be stored for at least the next six months and will be deleted at the end of the pandemic.

"Downloading the app is one more thing we can do to help flatten the curve, to help protect nurses and doctors, friends and families and ourselves and to help us on the pathway back to doing the things we love to do as a nation," Mr Hunt said.