  We present a mobile app solution to help the containment of an epidemic
outbreak by keeping track of possible infections in the incubation period. We
consider the particular case of an infection which primarily spreads among
people through proximal contact, via respiratory droplets. This smartphone
application will work offline and will be able to detect other devices in close
proximity and list all the interactions in an anonymous and encrypted way. If
an app user is tested positive and so is certified as infected, the application
notifies immediately the potential contagion to the devices in the list and
suggests to start a voluntary quarantine and undergo a medical test. We believe
this solution may be useful in particular in the current COVID-19 pandemic and
moreover could be used to prevent similar events in the future.
