Gnome Clocks - Clock application designed for GNOME 3
T-Clock Redux - T-Clock Redux in an enhanced fork of Stoic Joker's T-Clock 2010 with ISO week number support...
KTimer - KTimer is a little tool to execute programs after some time.
Insane Alarm - Wakes you up no matter what! Features - obscenely loud blaring emergency alarm sound.
Talalarmo - Minimalistic android alarm
VisualCron - VisualCron is an automation, integration and task scheduling tool for Windows.