The free game Who’s at the Door? turns the iPhone Duo into a door that you unfold to peek and fold shut when a villain lunges. Your reflexes are timed to the millisecond, and only a real flinch against a real lunge scores.
Developer Stefan Van Damme released the game on the App Store on October 27, and it also plays on any iPhone with a swipe and a tap. The app carries a 17+ age rating because of mild horror themes and unrestricted web access.
Who’s at the Door has you unfold the iPhone Duo to peek and fold it shut
You hear and feel every knock, then unfold the iPhone Duo slowly to open the door. If a burglar, a raccoon with your keys or another villain lunges, you fold the phone shut as fast as you can.
Not every caller is a threat. A friendly visitor such as the pizza guy should stay at an open door, and closing it on a friend earns a cheeky comeback instead of a score.
You lose the round if you close the door too early, and the villain gets you if you close it too slow. Some villains only bluff and never strike, so shutting the door at the first scary face does not score.
You can turn on a live hinge-angle readout to watch the door open degree by degree. The same hinge angle drives Duometry, an angle guessing game.
Two modes and a cast of 15 callers keep the rounds changing
Knock Knock! gives you endless rounds of knocks, peeks and quick closes. Flinch Three is a daily challenge with three flinches and one run a day, and your best time counts.
The cast has 15 hand-illustrated callers, plus a rogues’ gallery that includes Bandit the raccoon and the Porch Pirate. A Who’s Who yearbook lets you study them before you open the door.
At Halloween the regular cast steps aside for trick-or-treaters such as ghosts and a little witch, but the alien that arrives with the UFO never bluffs. At Christmas the room gets a wreath and festive decorations.
Game Center leaderboards track Fastest Close and Flinch Three. The game also keeps your own top 10 fastest closes and shows a history chart of how your reflexes improve over time.
Who’s at the Door is free on any iPhone with one optional purchase
On other iPhones you swipe the door open and tap to close it. The game is free, and one optional purchase removes all ads for good on every device signed in to your Apple ID.
The room switches between day and night with Light and Dark Mode, a cozy soundtrack plays underneath, and the game supports Reduce Motion. You need iOS 27.0 or later and about 124.8 MB of free space.
