Talalarmo - Minimalistic android alarm
Hourglass - Hourglass is the most advanced simple countdown timer for Windows.
Insane Alarm - Wakes you up no matter what! Features - obscenely loud blaring emergency alarm sound.
Gestimer - For those little reminders during the day
Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
wnr - Better than pomodoro, this timer app balances work and rest.