When it spots a second person looking at the screen, it alerts the user - by sending a picture of the offender with rainbow vomit streaming from their mouth, Daily Mail reports.
Google researchers Hee Jung Ryu and Florian Schroff will reveal their app next week at the the Neural Information Processing Systems conference in Long Beach, California, according to Quartz.
The app, dubbed an 'electronic screen protector', can recognize a person’s gaze in 2 milliseconds, the researchers say.