There's a new tool in the arsenal to stop the spread of coronavirus. It's a do-it-yourself contact tracing tool developed at Florida International University. Psychologist Jacqueline Evans says the "Cog Tracer" is a free and private app you can use the minute you start feeling sick. It works by asking specific prompt questions to better recall who you've come into contact with. She says it uses investigative interviewing tools to dig deeper into people's memories it also asks people to visualize themselves in certain places -to come up with a more complete list.