Stop Corona is an app that's been verified by the Austrian Red Cross. You can use this app to create a list of contacts that gets stored internally and anonymously in the app. The purpose of the list is to warn your list of contacts that someone around them is infected if you become infected by Coronarivus.
By adding a list of people you've had contact within the last 48 hours, it becomes much easier to be warned if any of them has been infected by the virus or you're the one infected. The alert system also notifies doctors so they can contact these patients and reduce the chain of contagion.
Keep in mind that a good amount of people need to download and use the app for it to be effective. Plus, it is advisable that every time you're in contact with a person you record a new 'digital handshake' to keep an updated list of the people you've seen during the last 48 hours.
Stop Corona helps you prevent the spread of Coronavirus with this simple but effective method. By anonymously informing groups of people about identified infections, you can take extreme precautions and contribute to stop the virus.