Set timer for 15 min. Start the online timer set for 15 minutes. Alarm notification is optional.
How to use 15 minutes timer
The timer will tell you when your 15 minutes has run out. It will keep counting upwards instead.
Sound notification (alarm) is optional. You can keep the timer running in the background if you for example open a new tab. If you have sound notification the timer will tell you when time is up.