Big Clock is a simple, free, clock and alarm solution. It uses your system time in it's full screen display and if you want, you can set a time for it to alert you, just like a conventional alarm clock.
What's new in Big Clock
Controls via menus
Different sizes for minimized window
Set which screen to display on when 2 displays are present
Window is hide-able and will reappear/fullscreen when the alarm goes off