As we search for a way out of the global coronavirus crisis, there’s been plenty of discussion surrounding a potential COVID-19 tracing app. Many of us carry a mobile phone with us wherever we go, so it seems logical to use this pre-existing infrastructure in the transition towards a ‘new normal’. But how tricky is it to make such an app? What’s more, what challenges must be overcome for it to be an effective measure of preventing virus transmission? In this episode of the Big Questions podcast, Dr Grant Blank from the Oxford Internet Institute, who studies the social and cultural impact of the internet and new media, offers some thoughts.