Thanks to Crave for pointing out the Enso Clock.
It's specifically designed for use in yoga or workout sessions.
Instead of having the digits count down, which can be distracting, it has a circle around the perimeter that slowly fills in.
You can also create sessions consisting of up to fifty timed periods. Rather than signalling the end of each period with an obnoxious beep or buzzer, they have chosen more soothing sounds, like a "singing bowl" or "tingsha bell".