React Diffuse Lock
Puzzle
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
A blank canvas. Two chemicals spread and react. Spots appear. Or stripes. Or a labyrinth. Which pattern depends on two numbers you control. Find the ones that match.
React Diffuse Lock is a puzzle built from the equations that explain why leopards have spots.
In 1952, Alan Turing — the mathematician who helped end the Second World War — published a paper proposing that the patterns on animal bodies emerge from two chemicals reacting and diffusing through tissue simultaneously. One chemical activates itself and the other. The other suppresses the first but spreads faster. When these two processes compete across a surface, the uniform state breaks into structure spontaneously. No blueprint. No instruction. Just chemistry finding its own equilibrium.
The game gives you a live simulation of this system. Two chemicals spread across a canvas in real time, 300 steps per second, updating every cell according to the same equations that produce every stripe on every zebra and every spot on every leopard. The canvas begins as a uniform amber field. Then dark regions nucleate, grow, and compete — eventually settling into a characteristic pattern.
Two sliders control the system. The feed rate determines how quickly new activator enters. The kill rate determines how quickly inhibitor is removed. These two numbers — each adjustable to the nearest thousandth — entirely determine what pattern emerges.
At one setting, isolated spots appear, scattered like dalmatian markings on a pale background. Move the feed rate slightly lower and the spots elongate, connect, and become stripes. Move it slightly higher and the spots merge into a labyrinthine network of connected channels — the same texture as a giraffe's patches, or the ridges of a fingerprint, or the surface of a brain coral. Move it lower still and the spots begin to divide and wander, never settling — the mathematical edge of chaos.
A target pattern is shown in the corner of the canvas: generated by running the same simulation at the correct parameter values. The player adjusts the sliders until the canvas matches it. The match meter fills only after the simulation has settled — watching the meter tick up while the pattern is still forming is not allowed. The player must understand the system well enough to find the right zone, not just scan through it.
The difficulty is the sensitivity of the system. The zone that produces spots is only a few thousandths of a unit wide. Moving outside it by the smallest increment produces stripes instead, or labyrinth, or nothing at all. This sensitivity is not a game mechanic invented for challenge. It is the actual mathematical property of the system — the same property that makes every animal's markings unique, because the effective feed and kill rates in any individual's skin tissue during the weeks when those patterns form are unique to that individual.
Your fingerprint ridges formed this way. The parameters were set by your personal skin chemistry during weeks ten through sixteen of your development. The game asks you to find, by hand, what your skin found automatically.
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The developer, Frank Rogers, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
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Information
- Seller
- Frank Rogers
- Size
- 11.2 MB
- Category
- Puzzle
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
- English
- Age Rating
16+
- 16+
- Copyright
- © Frank, 2026