Millions of people have installed smartphone applications which are designed to notify users if it seems possible that they have been exposed to the Covid-19 virus through their contact with other people known to be infected. Bluetooth® technology has been used in many of these applications. How was Bluetooth used? What worked well and what did not? What was the role of the Bluetooth SIG? What might the future hold as we look to learn lessons and be better prepared for the next public health crisis of this magnitude? Martin Woolley from the Bluetooth SIG will examine these questions.