For three years the West Virginia University Rockefeller Neuroscience Center has equipped 30,000 people with smart rings and smartphone apps to determine, before any signs of illness, whether they had influenza. So it required only some computer algorithm adjustments to launch a pilot project in March to monitor 200 front-line healthcare professionals for COVID-19 and determine the presence of infection and potential for contagion 24 hours before flu symptoms emerge.

Amid the country's growing substance abuse crisis, last year the FDA cleared reSET, a mobile app that tracks substance use, cravings, and social triggers to treat dependency on alcohol, cocaine, and cannabis. The FDA's clearance makes reSET one of the first prescription "digital therapeutics"--an emerging class of evidence-based interventions that are predominantly driven by software rather than drugs. Andy Coravos is is the CEO of Elektra Labs and a member of the Harvard-MIT Center for Regulatory Science. Earlier this year, digital medicine company Akili Interactive announced that its video game for children with ADHD demonstrated a statistically significant improvement in a randomized, controlled clinical trial. That milestone paves the way for what could be the first prescription video game.