A D D Timer, a simple timer application for Windows that helps remind you when a set time is up. The application allows you to launch multiple instances with different titles and time periods that are based on settings passed to it from an XML file.
A high resolution Countdown Timer and Stop Watch in .NET
...It use a QueueTimer (via PInvoke) for high resolution timing and System.Timers.Timer for normal resolution.
It also allow users to save, load and remove current state to/from a XML file.