Apple and Google developed a new API for iPhone and Android that would allow app developers to create contact tracing apps for the novel coronavirus. The Apple-Google approach relies on Bluetooth connectivity between devices to determine the risk of exposure of an individual to a person who tested positive to COVID-19. The object of such apps is for medical systems to be able to perform quick contact tracing and react accordingly. Patients can be isolated earlier and tested for COVID-19 with the help of such apps. But, crucially, participation is voluntary. It’s up to iPhone and Android users to opt-in. When they do, their privacy will be protected, and neither Apple nor Google will collect any data about users. It’ll all stay on their phones.