Did you know that every integer can be composed of a sum of prime numbers ?

PrimeTimer for WatchOS has a keypad that allows you to quickly compose any number within 59 minutes from the only first 8 prime numbers. Try it !

17 + 13 + 11 + 1 = 42

When you add all the first 8 prime numbers you can sum up to 59 so 59mn

Once you start the timer you can see the ring animated to mesure visually the countdown

Long press on the ring shows the starting time and ending time

Double tap on the ring to cancel the timer

Force touch on the screen and you access a "classic" keypad

When you type the minutes add up number by number

Tap on the "s" key to type the seconds

With the Digital Crown you can increment seconds by a 5s step up to 59s

When the minutes are set you can no longer type, the keys are grayed out

Double tap on the minutes and seconds input to clear it back to 0

The other keypad allows you to set the End Time with the Digital Crown or with the help of the buttons

Because WatchOS limit the time an app can run in the background to 1 hour, you can only set the countdown to 60mn

You can set the Graphic Circular complication on your Watch to access the app and see the timer's animation

The timer's icon is green in the center when it's active

When the timer is up, you receive a notification if the app is in the background

The app is translated in English and French

When the timer is up, Force Touch on the screen to access the history of the last entry