DuoFeels like the real thing
The whole side is the button — tap it, slap it, palm it. A deep click, a proper clack, and a flag that falls. Timing is timestamp-based, so it never drifts.
Chess clock & timer
Duo turns your iPhone or iPad into the clock beside the board. Tap anywhere on your side — even a full-palm slap counts. White plays on paper, Black plays on ink.
Built for the board
The free clock is complete: every essential below is included, forever.
The whole side is the button — tap it, slap it, palm it. A deep click, a proper clack, and a flag that falls. Timing is timestamp-based, so it never drifts.
Sudden death, Fischer increment, Bronstein, simple delay, multi-stage FIDE controls, per-player handicap and hourglass. Byo-yomi and penalty overtime with Pro.
A red glow, chimes at 60 and 30 seconds, a per-second tick under ten, and haptics you can feel through the table. Never lose on time in silence.
Lay the device flat and each half rotates to face its player — a tournament clock sitting beside the board. Works on iPhone and iPad.
Every game ends with a shareable game card — winner, moves, think times and the clock race in one designed image. Post it or save it.
Game history, think-time habits and head-to-head records for every opponent. Duo records every game from day one, so Pro unlocks your past games too.
See it in action
Pay once. Own it forever.
The free clock is never limited for play — Pro adds depth, not reliability.
$0The complete clock, forever
$6.99One-time purchase · family shareable · local pricing varies
No account. No ads. Private.
Player names, game history and settings live on your iPhone or iPad. There is no Duo server and no account to create.
No advertising, no ad networks, no selling data. Anonymous, aggregate usage counts help improve the app — never names, never games.
One clear one-time purchase. Nothing renews, nothing expires, and the free clock never nags you mid-game.
Chess, Scrabble, Go, shogi & every board game
Free to play, ready in seconds. Requires iOS 17 or later, iPhone and iPad.