Poliglot News LLC

A small software company registered in the United States, started in 2026 by Tamir Cohen. We make puzzle games for iPhone. Doku is the first one.

Email tcohen@poliglotnews.com.

Doku

A logic puzzle for iPhone. It isn't on the App Store yet. We're still building it.

Each colored region on the board holds exactly one answer. The marks inside a region say where other answers can't sit.

How it plays

Boards run from 4×4 up to 9×9, split into colored regions. Every square in a region shows the same glyph, drawn as small ticks around an empty center. You're looking for the one square in each region that doesn't break any rule on the board.

There are three ticks.

A green tile with one tick above, below, left and right of the center.
Horizontal and verticalNo other answer directly beside it, or directly above or below it.
A green tile with four diagonal ticks at the corners of the center.
DiagonalNo other answer on any of the four corners.
A green tile with eight ticks radiating in every direction.
CombinedTicks add up. This one blocks all eight neighbors.

It doesn't matter which of two squares carries the tick, only that one of them does. Squares in the same region never conflict, since only one of them can be the answer.

Single tap marks a square you've ruled out, and you can drag to mark a run of them at once. Double tap commits a square as its region's answer. The board checks it right away: a correct answer gets an ink frame and a dot, a wrong one leaves a red cross and costs you a chance.

A perfect solve is one move per region. Numbered levels give you three chances, and using all three restarts the level without losing your place.

Sixty levels

Six chapters, each built around one rule. Boards start at 4×4 with eight regions and reach 9×9 with as many as twenty-two.

1 · First Lines
The horizontal rule. 8 levels.
2 · Uprights
The vertical rule. 8 levels.
3 · Crossings
Both lines at once. 10 levels.
4 · Corners
The diagonal rule. 10 levels.
5 · Confluence
Rules that combine. 12 levels.
6 · Depths
The full board speaks. 12 levels.

Every board is checked before it ships: a solver confirms it has one solution, and a second pass confirms that solution can be reached by reasoning. You're never asked to guess.

Screens

Doku home screen with Start Journey, Daily and Journey buttons.
The home screen.
A 6 by 6 Doku board partway through, showing four confirmed answers.
A board part-way through.
The in-game rules sheet explaining the horizontal, vertical, diagonal and combined rules.
The rules sheet, reachable from any board.
The level map showing numbered levels along a winding trail.
The level map.
The Doku tutorial teaching the first rule on a small board.
The tutorial.
A Doku board rendered in the dark theme.
Dark theme.
The banner shown after solving a Doku board perfectly.
A perfect solve.
The Doku settings screen with theme, text size, sound, haptics and usage data options.
Settings.