TimeClue is a free, simple and tiny time reminder software that fades your desktop into a bluish color at fixed intervals.
TimeClue is designed to help you develop a habit of resting your eyes every 15 minutes (recommended for heavy computer users).
Alerts are raised at fixed time, as otherwise that habit will never stick.
To see TimeClue fader in action, just start the program, then click its icon in the system tray.
To quit TimeClue, right click the icon and choose Exit from the shortcut menu.
To configure the application, choose Options from the shortcut menu.