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Getting out of lockdown: the role of tracker apps

23 April 2020: tracker apps could play a crucial role in helping the world out of its current lockdown. Kirstin Gillon of ICAEW’s Tech Faculty explores the benefits and potential pitfalls.

Tracker apps are often cited as a key element of an exit strategy from current COVID-19 lockdowns around the world. These are apps on our mobile phones that will help to track the spread of the virus and enable more targeted interventions where there are outbreaks. They can help most people get back to some kind of normal life while keeping a lid on the virus until a vaccine can be found. Many governments around the world are looking at these apps and the UK government recently announced its own NHS contact-tracing app, which is being tested in April. 

What are they doing?

The idea of a tracker app covers a wide range of functionality and technologies that have different implications, especially around privacy. The main kind of app being looked at in the UK and across Europe and the US focuses on contact tracing via Bluetooth technology. The app will record identifiers of other phones that are within the required proximity for enough time to enable the transmission of the virus. If an individual is later tested as COVID-19 positive, all the relevant contacts will then be alerted that they are at risk. This is classic public health contact tracing done at a scale which is unlikely to be possible through manual methods. 

However, a range of other functionality and technology is also being deployed or proposed by other countries, and which can potentially link into contact tracing: 

  • GPS, location data and  scanning of QR codes are being used to help identify individuals in particular places at specific times.
  • Some countries are monitoring those who have tested positive or been put into quarantine to make sure they don’t leave their houses or use public transport, for example, giving them a red, amber or green symbol on their phone to display which allows them access to public spaces (or bars them).
  • There is some tracking of general population movements around cities and countries to identify whether people are complying with restrictions, for example the aggregated data released by Google maps which showed drops in the use of public spaces. 
  • There are apps which help to identify or monitor symptoms, such as the UK’s app covid.joinzoe.com. The data they collect shows scientists how the virus is spreading in the absence of widespread testing. 

How secure and private are the apps?

The idea of tracker apps has raised concerns about the security of data and the protection of privacy. 

The contact tracer apps using Bluetooth are generally felt to be the most secure and private solution. They don’t have to store location or personal identity data as they use an encrypted identifier linked to the phone. Other approaches based on GPS or location tracking  have been used in some parts of Asia, and raise greater concerns. 

The Bluetooth approach is also largely decentralised. Contacts are simply notified of their risk when someone tests positive. The data can be erased when it relates to contacts no longer relevant for contact tracing. The main interaction with central authorities would be around the testing process and authentication to minimise the risk of false reporting and trolling. The UK app envisages a dual approach –sending out an amber status to contacts when an individual reports symptoms on the app and a red status where they test positive.  

However, one drawback of this minimal approach is that it doesn’t give the government a dataset that it can use about the spread for other reasons, such as resource planning. Consequently, governments might want users to input other data into the app so they can do more analysis. For example, the UK app asks for the first three letters of the user’s postcode if they enter that they have symptoms, which could be used to help with NHS planning. 

What else needs to be in place?

While technology can help, it’s not a silver bullet. It needs to work with several other elements. In particular, these kinds of trackers are based on mass testing so that anyone who suspects they have COVID-19 can be quickly tested. A key aim is to identify carriers of the disease in the early days before they develop symptoms. Consequently, unless there is timely testing, it will be too late to contact trace effectively and stop the spread. Alternatively, large numbers of people could be needlessly self-isolating if it is purely based on suspected symptoms. 

There also needs to be a critical mass of adoption. Academics at Oxford University  estimate that 60% of the population would need to sign up for an app for it to be effective in reducing the spread of the disease. Therefore, the app needs to work, be simple to use and be trusted. While there is evidence that many people are in favour of such apps and would be happy to use them as a way out of the lockdown, this still needs to be translated into action. It is assumed that the UK government would not want to mandate such apps, they would be voluntary. This will, therefore, require a big effort to get to 60% adoption. 

A final consideration is interoperability. How do different apps work across different phones? Once international borders open again fully and travel restarts, can these apps help to track people across borders? Google and Apple recently announced that they will be supporting efforts for Bluetooth contact-tracing apps, providing APIs to help the transfer of data between phones and apps. Longer-term, they are looking at integrating the functionality into their operating systems, reducing the need for individual apps and improving the security and efficiency of the process. 

What about governance and exit?

Even if the apps are viewed as appropriate, there are still questions about who will police the use of data, especially personal data, and what kind of oversight should be in place. And finally, when does this tracking stop?  

There are many concerns that governments will make land grabs for surveillance powers. In current circumstances, many citizens will be happy to provide this data if it enables economies to open and health services to function. But this doesn’t last forever. The question of how to exit from this stage of containment measures will need to be considered to build trust and encourage adoption.  


Tracker apps are likely to play a role in helping governments do traditional contact tracing in new ways that can be scaled up quickly and easily. As such, they will be an important component of exiting the lockdown strategy. However, success will be dependent on scaled-up testing that is accurate and available to those who need it. It will also need very high levels of trust from the public. The Bluetooth approach appears to provide a workable solution that minimises security and privacy risks, but a huge amount of work will be needed to achieve the level of mass adoption required to make it an effective tool.

For the latest news and guidance on the ongoing impact of COVID-19 for businesses and accountants, visit ICAEW’s dedicated coronavirus hub.