The new season's fourth episode, Hang the DJ, explores the dark pitfalls of app-based dating, and the software Georgina Campbell and Joe Cole's matched couple use to find each other might look familiar.
This is the same digital dating service glimpsed in the season three episode Playtest. Cooper (Wyatt Russell) is briefly seen using the application in the previous series.
The mysterious dating app is no doubt Black Mirror's equivalent of Tinder, with a similarly vast user base since it also crops up in season four's opening episode, USS Callister. Elena is briefly seen swiping away on it while manning the front desk.