Northern Ireland's Covid-19 contact-tracing mobile phone app has become the first in the UK to launch - although tracing the app itself was a problem for some last night.
It is called Stop Covid NI and is aimed at interrupting the spread of coronavirus by finding those most at risk of catching it.
Should someone receive a positive test for the disease, they will have a unique code texted to the phone. Once the user gives permissions, the app will release data from the handset to a server so close contacts also using the app can be traced following a "digital handshake" between their devices, Stormont's health department said.
The intention is to alert close contacts of a patient within a day or two of a positive test.
The software's use will be voluntary and identifiable information will not be stored to comply with data protection regulations, an official told the health committee of Assembly members.
The operating system is designed by Google and Apple and requires Bluetooth to remain on.
Health Minister Robin Swann has urged the public to download and activate the new mobile phone app which will alert users if they have been in close contact with other users who have tested positive for Covid-19.
However, some smartphone users on Twitter were unable to find the app.
Typing the name of the app into the search bar of Google's Play Store did not find it, while a number of web pages that contained direct links to the download displayed an error message.
It's believed this is because the app was supposed to officially launch today, but news leaked online and thousands managed to download it early. Others had problems finding it, and a source suggested the app had not yet been indexed in Google's Play Store search engine.
Ciaran McCauley, who helpfully provided Twitter users with a direct link, tweeted: "Android users - the StopCovidNI app - Northern Ireland's newly-launched contact tracing app - is very tricky (near impossible) to find with a basic search on the Google Play Store right now (the CovidCareNI app is not it)."
Eight more positive cases of coronavirus were detected in Northern Ireland, the Department of Health said yesterday. The total number of people who have been infected is 5,938. No new deaths were recorded, leaving the total in the region at 556, while the 'R number' transmission rate is between 0.5 and 1.