Our entire school uses visual timers to help support students of all abilities anticipate, recognize and manage transitions. The large visual timers are not convenient to carry with us to the outdoor learning yard, park or on community walks.
The App Store for Apple users has a couple of good free timers:
Children's Countdown - Visual Countdown Timer, is programmable to as little as 10 seconds, has a child mode which hides the buttons when the timer is running. It also reveals an image as the timer is counting down
VisTimerFree - counts down from 1-10 minutes and is a simple orange visual countdown