Duometry is a $2.99 game that gives you a target angle and asks you to match it by folding the iPhone Duo. You make your best guess, lock it in, and find out how close you came.
The app comes from Arno Appenzeller, the developer behind PiPifier, Glimpse 2 and the µBrowser Watch web browser, and it is on the App Store.
You match the angle by folding the phone or turning an on-screen dial
Each round shows a target angle, and you either fold a compatible device to what you think the angle is or adjust the on-screen dial. Then you lock in your guess to see how close you were. The phone has to be a hinged device for the fold to count, which is where the iPhone Duo comes in.
The iPhone Duo suits a game about angles because it can sit closed, flat, half folded like a laptop or propped open like a tent. That range gives Duometry a lot of material to work with.
Solo play runs for 5 or 10 rounds, and the goal is to beat your best score. You can also pass one device between 2 and 8 players for a friendly competition. Everyone’s guesses stay hidden until the shared reveal, so you find out who came closest and compare scores before the next round.
A daily challenge with three targets tests your angle sense and visual memory
Free Measure mode lets you explore angles at your own pace with the dial. On hinge devices, it reads the fold angle of the device directly, which makes it a simple angle gauge. Hinge Angle Meter takes the same approach at $0.99, reading the hinge as a live angle gauge.
The daily challenge gives you three targets to match each day. Different daily modes put your angle intuition and your visual memory to the test, which gives the game a reason to open again after the first few rounds.
Duometry plays offline and needs no account. It runs on iPhone, belongs to the Casual games category with a 4+ age rating, and the developer says it collects no data.
Duometry is a 4 MB download that needs iOS 17.0 or later, while a puzzle game like Orisuji weighs in at 214.3 MB.
