Apple and Google are working together on an ambitious plan to alert people who have come in contact with coronavirus patients — here's how it will work (AAPL, GOOGL)

· Apple and Google are working together on a digital contact tracing system that would use Bluetooth technology to alert users when they've been in contact with someone infected with COVID-19.
· The system is opt-in only, meaning users must give their explicit consent and choose to participate in the program.
· Apple and...