Chess Clock (Merkmatics)

Last modified
Wednesday, October 4, 2017

Description of App

A World-Class Game Clock for iOS. Updated for the new iPhone 5.

The most accurate, high performance, customizable and user friendly game clock on the App Store.

It provides the highest accuracy timing that iOS allows and has more features than any other game clock on the App Store. If you think there's a feature missing let us know and we'll consider adding it.

Why would you pay more for an app with fewer features, less accuracy and worse customer support?

If you like the app please write a review or give it a rating. If you have any difficulty using the app or you want a new feature let me know at I’m grateful for your comments and support.


  • Each player has a fully customizable clock that allows configuration of:
  • Start time
  • Increment/delay time
  • Increment sound (turn sound on and off as well as sound choice)
  • When to begin displaying tenths of a second
  • Accurate to 1000th of a second
  • Displays the number of moves each player has completed
  • Times and increments can be set with 1 second resolution
  • Ability to select which player starts the game
  • Negative Time
  • Clocks can count below zero
  • This is a configurable setting (off by default)
  • Ability to turn off the end of game sound
  • Optimized for iOS 6 (compatible with iOS 5 and above)

Delay Settings

  • USCF Delay (clock doesn't start counting down until the delay is over)
  • Fischer compensation (time added per turn accumulates)
  • Bronstein compensation (time added per turn does not accumulate)
  • No compensation (just set the increment time to zero)
  • Configurable Increment Notification System
  • Screen flashes and a quiet sound is played when your increment runs out
  • Individually configurable, each player can decide if they want increment notification and can choose between 3 different sounds

Handles interruptions smoothly

  • Never lose your place in the game. Games are saved when you receive a call or close the app and restored when you reopen the Merkmatics Chess Clock.
  • Games can be easily paused and resumed at a later time

Simple, Elegant look and feel

  • The active player's timer turns green or blue when their turn begins
  • A subtle "click" sounds, when you complete your turn, just like a real chess clock
  • Two end of game sounds, a simple two-tone beep and a old school video game sound
  • Small secondary display shows your opponents remaining time
  • About page that allows you to email support from inside the App

Intelligent Power Management

  • Clock is optimized to improve battery life
  • iPhone/iPod Touch won’t dim or lock during a game
  • Still dims and locks when a game is paused to conserve power
  • Option to use a black background to save power

I use the Merkmatics Chess Clock primarily for chess but it will work for any two-player game where you want to add a time component to the game play. It will work well with Go, Scrabble, Checkers, Backgammon and many other games.

If you would like to request a new feature, report a bug, or if you have suggestions about how to improve the app please let me know at

Thank you for downloading Merkmatics Chess Clock, I hope you enjoy it.



Free or Paid


Apple Watch Support

Not Known

Device(s) App Was Tested On


Accessibility Comments

This is an extremely accessible chess clock with a simple interface that gives easy access to the full range of features. The clock counters for each player are large buttons that each occupy the full width of the screen in portrait mode and about a third of the vertical extent of the screen at the top and bottom. I find it easiest to trigger a clock by touching anywhere on the large button on the bottom or on the top part of the screen and split tapping, which freezes the counter and starts the counter on the opponent's clock. Flicking left from my clock gives information of the number of moves and time on my opponent's clock. Apart from the player clock counters, and the information on the other player's clock counter time and number of moves that is available at either end of the display, there are 3 buttons in the middle strip of the screen: a "Reset" button to the left of center, a "Pause/Resume" button to the right of center, and in the very center of the screen there is an unlabeled button for accessing the "Settings" screen. (This is the only unlabeled element in the app, so I've selected the "Most buttons are clearly labeled" designation rather than "All buttons are clearly labeled", but given the simple layout of the screen and the accessibility of everything else, it's rather obvious that this must be the way to access the settings options, which are all configurable with VoiceOver.)

There's a nice audible alert at the end of the delay time period, which is 10 seconds by default, but is separately configurable for either player with picker items under Settings. Double tapping the "End of Game Alarm Sound" will play a sample of that sound, as well as change the setting.  The Settings options also include options for button color and background color, but I doubt these are designed with low vision users in mind.  It would be useful if some low vision users could try this app, and supply feedback to the developer for these options.

If you pause the clocks, you'll notice that flicking or reading through the entire screen will add a "dimmed" announcement with no corresponding button.  I have a "Vertical Navigation" setting in my rotor that I use to easily flick up and down between either counter clock and through the unlabeled button for reaching "Settings".  Then, when I use the chess clock app in portrait mode,  I can flick up to the "Settings" button and either left to the "Reset" button or right to the "Pause/Resume" button.  However, if you've paused the clocks, then touch the bottom clock and flick up using the vertical navigation setting, you'll hear the first clock time, then "dimmed", then the second clock's time.

It's also possible to use the chess clock app in landscape mode.  In that case, the two clock timers occupy the bottom half of the screen in landscape mode, with the timer at the top appearing in the left half of the screen, and the timer at the bottom of the screen appearing in the right half of the screen.  In this mode, flicking left from the two clock counters only gives announcements of the number of moves associated with the opponent's clock, since the timers for both players are directly available at the bottom of the screen.  The top half of the screen in landscape mode contains the buttons for "Reset", "Pause", and the unlabeld button for accessing "Settings".  The fastest way to pause in this mode is to have your rotor set to "Vertical Navigation", flick up from the button in the bottom right to the "Pause" button and double tap.  Or, you can do a four finger tap in the top half of the screen to move to the first element (the "Reset" button), then flick right to "Pause" and double tap. 


VoiceOver Performance

VoiceOver reads all page elements.

Button Labeling

Most buttons are clearly labeled.


The app is fully accessible with VoiceOver and is easy to navigate and use.

Other Comments

This app is available internationally, but localized in English. On a spot check of app stores in several countries, it was available in every store I tried except for South Africa. It is frequently updated. The app requires iOS 5.0 or later. Time counter numbers are supposed to be large, but it would be useful to have comments from a low vision user on this feature.


1 people have recommended this app

Most recently recommended by Esther 8 years 11 months ago