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Built for Duo

Fourfold: Four in a Row

Drop discs to connect four against a friend or the computer, or solve 120 solo positions.

Justin McCahill · Games · $1.99

View on the App StoreSave

iPhone screenshots

Fourfold: Four in a Row — iPhone screenshots 1
Fourfold: Four in a Row — iPhone screenshots 2

How it uses iPhone Duo

Stand the Duo like a book so one player uses the inner screen and the other uses the cover. The board is mirrored between the two viewpoints.

What’s New

Version 1.7 ·

A clearer App Store page and small under-the-hood improvements.

App Store descriptionWritten by the developer.

Drop a disc, hear it clack into place, and line up four before they do. Fourfold is four in a row with a twist: your opponent can see where you're aiming before you let go, and so can you. Play a friend on one screen, play across the table on iPhone Duo, or take on the phone at three levels. On your own, there are 120 puzzles. WAYS TO PLAY - Pass and play: two people, one screen - vs Phone: a computer opponent at Easy, Medium or Hard - Two sides (iPhone Duo): inside versus outside, each on your own screen - Puzzles: 120 positions to win in 1, 2 or 3 moves ON IPHONE DUO Open the phone and stand it up like a book. One player sits in front of the board on the inner screen; the other plays on the cover screen from the far side, seeing the board from behind, just like a real one: drop a disc on your left and it lands on their right. Close the phone and the cover becomes its own little game box: a full game, or Puzzles. 120 PUZZLES Each puzzle drops a position on the board and asks you to win in 1, 2 or 3 moves while the phone defends as hard as it can. Every puzzle has exactly one winning first move. Stuck? A hint lights the column. FIVE SKINS, FIVE WAYS TO DROP - Classic: plastic discs that bounce and clack - Neon: glowing rings that streak down and flash the column - Candy: gummy discs that stretch as they fall, wobble on landing and throw sprinkles - Walnut: heavy wooden pegs that thunk, shake the board and puff sawdust - Cosmos: planets with comet tails that land in a burst of stars Every skin has its own sounds, haptics and its own celebration when someone gets four. Start a new game and the slider pulls: every disc pours out the bottom. PRIVATE BY DESIGN No internet, no accounts, no tracking. On iPhone Duo, iOS only lets an open phone show an app on its cover screen while the camera is running, so two-sided play keeps the camera on at low resolution. Every frame is thrown away unseen and nothing is recorded. One price, no ads, nothing to unlock. Just a board, two colours and a lot of trash talk.

Fourfold: Four in a Row on iPhone Duo: FAQ

Is Fourfold: Four in a Row optimized for iPhone Duo?

Yes. Fourfold: Four in a Row is Built for Duo: it uses the fold, Split View or the outer display. Verified on November 13, 2026 (Developer statement).

What does Fourfold: Four in a Row look like on iPhone Duo?

Stand the Duo like a book so one player uses the inner screen and the other uses the cover. The board is mirrored between the two viewpoints.

How much does Fourfold: Four in a Row cost?

Fourfold: Four in a Row costs $1.99 on the App Store.

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