I'm Jan. I make games as JPUI, and Fold Fish is a fishing game for iPhone Duo — Apple's foldable. The short version is this: the hinge is the control. There is no joystick. The fold is the fishing rod.
A fishing rod already works a bit like a hinge. You open it back to load the cast, then you send the line out. That motion was sitting in the hardware. So the design started there, not with a virtual stick in the corner of the screen.
How wide you open the fold sets how far you cast. A tap sends the line into the pond. Hold, and you reel — while dodging the other fish. Three moves. That's it.
The game is built on the iPhone Duo hinge API, UIHinge. I don't have a long technical war story to tell about that, and I won't invent one. The work that interested me was making the phone feel like a rod, then getting the interface out of the way.
A pond across the fold
In book mode, the pond spans the unfolded screen. Fish swim right across the hinge. It's a living pond, from sunrise to stars — day and night on the same stretch of water. You hook something, you land it, you fill in a catch atlas: catch and discover every species. Along the way there are coins, helpers, and Foldfish Gold.
The App Store listing puts the wildlife mildly: dozens of fish — and a few surprises.
The same game on a phone that doesn't fold
Most iPhones still don't have a hinge. Fold Fish has to work there too.
On a regular iPhone, on-screen controls do the same job. I didn't want the non-foldable version to feel like a demo of the "real" one, or like an apology for missing hardware. It should just be a fishing game you can play on any iPhone. The Duo is where the hardware finally matches the metaphor. Everywhere else, the buttons stand in for the fold.
It requires iOS 18. It's free, with optional in-app purchases. No ads. I don't collect data from the app. Version 1.0.2, from 23 October 2026, is localized in 30+ languages.
Sometimes the catch is not a fish
I like a fishing game that can be cozy without being precious. The humour lives in the catch cards, and in what the fisherman says when the pond does something rude.
There's a moment in the gameplay where two fish bump into each other underwater, and he reports it like a traffic bulletin: "Bum. Dopravní nehoda pod hladinou." Boom. Underwater traffic accident.
And one of those atlas surprises is a frog. Land it, and the card reads: "PERFEKTNÍ! Žába — Tohle není ryba. Žába to ví. Ty teď taky." That's "Perfect! Frog — This isn't a fish. The frog knows. Now you do too."
The card doesn't really congratulate you. It just corrects you, politely. The joke doesn't need explaining. If you hook a frog, you already know.
Out in the world
On 2 November 2026, iGeeksBlog featured Fold Fish in a YouTube video. If you'd rather see the fold-to-fish motion than read about it, start there — or here:
If you have an iPhone Duo, open it like a rod and see how far the line goes. If you don't, the on-screen controls are waiting.
Top comments (6)
This is a lovely mapping of hardware to gameplay — using the fold itself as the rod makes the cast feel physical rather than just a button press. I also liked that the non-foldable version is a real alternative rather than an afterthought, and the catch cards sound like a nice place for the game's humour to live. Did playtesters find the hold-to-reel timing intuitive on their first try, or did it need tuning?
Thank you, that's exactly what we were going for: the fold should feel like a real cast, and nobody on a regular phone should feel left out. Great question about the hold-to-reel timing. I want to give you a real answer rather than a guess, so I'll check our notes and come back to it here.
Honest answer: I don't have proper playtest data to share yet. Fold Fish is a small solo project and the hold-to-reel feel is exactly what I'm watching in early player feedback. Did it feel intuitive for you on the first try?
Small update: Fold Fish launched on Product Hunt today. If you've got questions about the hinge-as-a-rod idea, happy to answer here or there: producthunt.com/products/fold-fish...
把折叠铰链当成鱼竿这个映射太妙了，甩竿力度跟着开合角度走，玩起来一定很有手感；非折叠机用屏幕控件替代的兜底也很贴心，期待后续的实机视频。
谢谢！Thank you, glad the hinge-as-a-rod idea lands. And yes, on regular phones the same fishing works with on-screen controls (tap to cast, hold to reel), so nobody gets a lesser version. A short real gameplay clip is already up on our Bluesky, @jpuidev.bsky.social, if you want a look.