Warning: This post contains SPOILERS for Countdown.
STX Entertainment's Countdown (2019) has a mid-credits scene, so we break down what happens and what it means. Over the years, there have been plenty of horror movies inspired by technology, specifically cell phones. In Countdown, the premise focuses on a particular app that tells users when they'll die. However, if they change their actions based on the information given to them by the app, they violate the user agreement and are tortured by a haunting figure until they die.
As seen in the Countdown movie trailer, the film follows young nurse Quinn Harris (Elizabeth Lail), who learns she'll die in just a few days. Teaming up with fellow Countdown user who's expected to die soon, Matt (Jordan Calloway), Quinn tries to figure out how the app is torturing its users so she can prevent her death and the death of her younger sister, Jordan (Talitha Bateman). Though Quinn is ultimately successful in saving herself and Jordan, and defeating the entity powering the app, the movie ends with the ominous reveal of the Countdown app receiving an update, teasing a sequel.
Also, Countdown has a mid-credits scene, though it doesn't further set up a sequel. Instead, the mid-credits scene catches up with phone store owner Derek (Tom Segura), who had delayed his Tinder date to help Quinn and Matt hack the Countdown app. The scene sees Derek at the end of his date, which he thinks is going well but is obviously going badly. The server is trying to get them both to leave, telling Derek the restaurant closed half an hour ago. The server walks off and Derek's date gets up to go to the bathroom. Left alone, the restaurant lights flicker and go out, with the screen cutting to black. The Countdown demon can be heard, then the sounds of Derek being killed, before the credits resume.
It's unclear how Derek was originally going to die, since users are only murdered by the demon if they break the terms and conditions agreement. We can presume that Derek was targeted because he hacked into the app and attempted to add more time to his life, violating the agreement in the process. He did the same for Quinn and Matt, but they'd already broken their user agreements. It should also be noted that, despite the scene playing after the ending, it actually takes place before Quinn defeats the Countdown movie app, which explains why Derek is killed after the resolution of the film.
In terms of what the mid-credits scene adds to Countdown, it doesn't work to set up the sequel and seems to be one last bit of entertainment - another jump scare - for moviegoers. That makes sense because there's sequel setup at the very end of the film, with Quinn receiving a notification about Countdown 2.0. That said, whether another movie in this universe gets made remains to be seen. The Countdown movie reviews have been largely negative, but if the film turns out to be a box office success, perhaps a sequel will get the green light. It's unclear what a Countdown sequel would entail, whether Quinn would face off against the app once again. No matter what, it's clear Derek won't be back after the events of the Countdown mid-credits scene.