ReRemind is a Windows Mobile service that plays a brief sound at a specified interval when reminders, missed calls, and voicemails are awaiting your attention.
ReRemind runs as a true Windows Mobile service -- it is a DLL hosted by services.exe. Therefore, ReRemind does not use one of the very few 32 processes available. ReRemind is also very light on available resources, relying on the built-in notification system
to scan for and raise notifications.
XDA home page: