At the start of the fourth season of the popular Netflix series Stranger Things, the character Eleven has lost her telekinetic abilities. But, thanks to some small-business innovation, viewers can now channel her powers for a vital task: ordering a pizza. 

Working with ad agency WorkInProgress and content creation company Unit9, Domino's released a new "mind-ordering" app in partnership with Netflix to promote the show's May 27 season premiere. The app allows users with a Domino's account to order a pizza simply by moving their head while looking at the screen. There's also a "Just for Fun" mode where users can explore the show's Hawkins National Lab and find Stranger Things Easter eggs.

The head movements necessary to place an order mimic those that Eleven (played by Millie Bobby Brown) makes when using her mind powers: App users tilt their head down and stare at an object to select it, and flick their head to the side to dismiss it. The promotional campaign also includes a three-minute "how it started" video featuring characters from the sci-fi series as well as a page on Domino's website designed by WorkInProgress with instructions on using the app.

"Domino's has a history of innovative ways of ordering," says Dan Corken, director of interactive production at Boulder, Colorado-based WorkInProgress. The food giant previously has introduced ordering through Amazon Alexa and Google Home, as well as by sending a text with the pizza slice emoji. "We're always looking for unique, fun, and technical ways to push the boundaries of ordering," he says. 

To create the app, WorkInProgress and London-based Unit9 started with already-existing facial recognition software. They then developed custom logic for the software so that the app could recognize Eleven's specific gestures, and employed testers to refine its accuracy.

"There were quite a lot of complexities on our side in terms of tracking the features whilst also looking at the position of the phone, because it's a 360-degree experience," says Shelley Adamson, creative director at Unit9.

If you're interested in developing a novel app to promote your business, that process might seem daunting. But, according to Derek Riley, the electrical engineering and computer science program director at Milwaukee School of Engineering, there are a variety of ready-made facial recognition software programs, and adding them to an app isn't significantly more complicated than introducing any other feature.

Adding facial recognition technology to an app can become more complex, however, if you decide to first customize the software as the Domino's app team did, which Riley says requires access to and knowledge of its code. "That improvement step is [also] the expensive part," he adds. Domino's declined to provide any information on the costs of the campaign.

The use of facial recognition technology comes with other concerns, including user privacy and bias. According to WorkInProgress, Domino's does not use or store user data from the mind-ordering app. To assuage users' privacy concerns, the app provides information about what it's tracking and how it uses your camera. 

In terms of accuracy, all facial recognition software programs have some bias, Riley says. Of course, the stakes are far lower for the pizza-ordering app than, say, for the technology's use in law enforcement. Riley stresses, though, that accuracy should remain a priority. "Just because it's low-risk doesn't mean we should tolerate bias in the algorithm," he says.