Countdown (2019) on Netflix

Plot summary

Courtney, a teenager at a party, is talked into downloading Countdown, an app that claims to know how long its users have left to live. Hers gives her three hours. Quinn Harris, a nurse at the hospital where Courtney's boyfriend Evan is admitted after a crash, dismisses his talk of the app until she installs it herself and reads that she has two days. Research turns up other users said to have died when their countdowns ran out, most of them dismissed as hoaxes, and a new phone does not help: the app installs itself. In a parking lot Quinn meets Matt, whose countdown gives him eighteen hours.