Pixel Chain

Pixel Chain is a small-canvas pixel editor where you do not choose colors freely. You choose from what the chain allows. HOW IT WORKS Every pixel you place is appended to a chain. From the second pixel on, a color is legal only when the SHA-256 of every color placed so far, plus that candidate color, ends in a run of zero bits. The number of zero bits is the level you pick when you create the canvas. Your palette swatches almost never pass that test, so they appear struck through. Underneath each one sits what you can actually place: the legal colors nearest to it, found by sweeping all 16,777,216 colors after every stroke. WHAT THAT FEELS LIKE The cursor walks left to right, top to bottom, and you cannot move it by hand — every color depends on the whole chain before it, so the order is fixed. Made a mistake? You can only clear from the end. There is no jumping back to repaint pixel 12. The result is that no two canvases share a palette, and the picture you end up with is a negotiation between what you wanted and what the hash allowed. LEVELS Level 1 leaves 8,192 legal colors in the entire 24-bit space. Level 10 leaves 16. The higher the level, the further the legal color sits from the one you had in mind, and the more the image drifts into something you did not fully author. Levels 1 to 4 are free forever. A single purchase — no subscription — opens levels 5 to 10. EXPORT Finish every cell and export a hand-written 24-bit BMP, scaled with nearest-neighbour so the pixels stay razor sharp. Or export a ZIP: many apps quietly re-encode a bare image while sharing it, and the ZIP keeps your bytes exactly as written. EVERYTHING STAYS ON DEVICE No account, no cloud, no analytics, no ads. Your artworks live in local storage and go nowhere else. Canvases from 8×8 to 128×128. Ten built-in palettes plus your own. iPhone and iPad.