The objective of digital shield is a help to normalize life after the massive quarantines every country is suffering right now. As the virus will be circulating around for an unpredictable ammount of time until a vaccine is developed. Economies must resume their workings but at the same time life and privacy should be respected. This application is not a "solve all" solution, it should be used with medical, pulic policy and other techonological tools.
The way this application works is by generating what is call a "contact" via bluetooth technology. A "contact" indicates 2 persons were physically close for an ammount of time. Those "contacts" are collected in a privacy focus way way in a central server.
Once a case of coronavirus is detected via a test, a "contact trace" is launched looking back in the past for all the people that this person was in contact with and alerting them. depending on the ammount of time passed, the secundary "contacts" can already be transmitting so a launch will also launch for them and so forth.
Is this an scam? All the source code and designs are openly available, there is no corporate or goverment backing at the moment. If you want to donate i'll gladly receive and put that money to the project, for now you can do it with github.
Is there any evidence this works? Singapore is developing something similar https://www.straitstimes.com/tech/singapore-app-allows-for-faster-contact-tracing
Oxford developed a study and recommends this type of approach http://www.ox.ac.uk/news/2020-03-17-infectious-disease-experts-provide-evidence-coronavirus-mobile-app-instant-contact
And older articles already pointed at the benefits at least from the simulation side
https://www.researchgate.net/publication/262023914_Epidemic_Contact_Tracing_via_Communication_Traces
What about other projects?
Other existing projects are positive, the objective of this project is to develop something functinal, but at the same time rise awareness that digital technology can help to combat covid-19 in a direct way.
What is the current stage?
Design and prototyping, you can see the designs in the Wiki