First Minister Nicola Sturgeon has thanked Scots after more than 500,000 people downloaded the new NHS contact tracing app.
The Protect Scotland app became available to download free onto a smart phone from Apple's App Store or Google Play on Thursday.
Just hours after its launch, Ms Sturgeon urged as many people as possible to get involved in the new tracing scheme.
Speaking in the Holyrood chamber on Thursday afternoon, she said: “The more people that sign up the better. Everybody who signs up is making a contribution.”
The app can alert users if they have been in close contact with someone who has tested positive for Covid-19 and advises them to self-isolate and get tested.
The app does not store details on an individual or their location but uses encrypted, anonymised codes exchanged between smartphones to determine close contacts with people who test positive.
A close contact is defined as someone who has been within two metres for at least 15 minutes.
If a person tests positive for coronavirus, they will be sent a unique code to their mobile and – with their permission – the app’s data will then be sent to a server so close contacts also using the app can be notified by text and advised to self-isolate.
Designed by software developers NearForm for NHS Scotland, the app uses the same technology as the Irish and Northern Irish proximity tracing apps.
On Thursday evening, following the news that more than 500,000 Scots had downloaded the new contact tracing app on the day of its launch, Ms Sturgeon then tweeted: "My thanks to the HALF A MILLION plus of you who have already downloaded the Protect Scotland app.
“Please keep spreading the word – the more who use it, the more effective it will be. We are in this together and together we can save lives.”
The NHS Scotland Test and Protect App can be found here.