Switzerland is getting ready to roll out a mobile phone app to alert people who have come into contact with coronavirus carriers. Mathias Wellig, CEO of Ubique, the company hired by ETH and EPFL to develop the tool, says it is designed to protect the identity of users and prevent their data from being used for other purposes. Andrea Büchler, president of the National Advisory Commission on Biomedical Ethics, says the app must also be voluntary and part of a broader anti-COVID-19 strategy that includes traditional methods for monitoring the virus.