Drystone

Drystone is a Suguru puzzle game that builds every board on your iPhone, the moment you ask for one. There is no library to run out of and nothing to download.

THE RULES ARE TWO LINES
The grid is divided into blocks. Each block holds the numbers 1 up to the number of squares it contains, so a four-square block takes 1, 2, 3 and 4. No two identical numbers may touch, not even diagonally. That second rule is where the thinking lives.

DIFFICULTY YOU CAN TRUST
Most puzzle apps get harder by hiding more numbers. Drystone solves each board the way a person would, then grades it by the hardest technique that solve actually required. An Expert board is one that genuinely demands an expert move, not one that simply left more squares blank.

HINTS THAT TEACH
Ask for help and Drystone shows you the next logical step and the reasoning behind it, rather than just filling in a square. Pencil marks clear themselves as you place numbers, and undo runs losslessly all the way back to the start.

A DAILY PUZZLE FOR EVERYONE
One puzzle a day, derived from the calendar date itself, so every player gets the same board. It starts gently on Monday and bites by Sunday, and it keeps a streak. The daily is free forever.

WORKS ANYWHERE
The app makes no network requests at all. Puzzles are generated on the device, so aeroplanes, tunnels and dead zones make no difference.

PRIVATE BY DESIGN
No account. No sign-in. No email address. No analytics. There is nothing to collect, because nothing ever leaves your phone.

ONE PAYMENT
Easy and Medium are free to play, and so is the daily puzzle. A single £2.99 purchase unlocks Hard and Expert, unlimited puzzles and the hint engine. There is no subscription and no advertising on either side of that line. The unlock works on every device signed in to your Apple Account, and it supports Family Sharing.

Simple rules. Endless moves.

Requires an iPhone running iOS 26.0 or later.