Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Timetaco - Create your own countdowns, as easy as 3, 2, 1
wnr - Better than pomodoro, this timer app balances work and rest.
Coountdown - 3 2 1 ! Create day counter on menu bar macOS. 🚀
Free Countdown Timer - Free Countdown Timer is a free, full-featured and user-friendly countdown timer for Windows
Padbury Clock Screensaver - Minimal screensaver for Mac