AlarmDroid - AlarmDroid is an alarm application that is only available on Android devices and possesses many interesting features.
Free Alarm Clock - Free Alarm Clock is a free, full-featured and user-friendly computer alarm clock for Windows.
Google Clock - Google Clock is an application of Google Inc.
Digital Clock 4 - Beautiful customizable clock with plugins
Sleep Better - Track sleep cycles, monitor dreams & improve bedtime habits
Gnome Clocks - Clock application designed for GNOME 3