Chronos fills the gap in Windows Mobile operating system by offering

Unlimited number of highly customizable alarms:

Alarms can be set to signal only on certain days of the week;
alarms can be one-time or repetitive;
alarm can notify you by playing sounds, turning on/off vibration, blinking the LED;
WAV and MP3 alarm files are completely supported as sound notification;
you can select custom sound stored in memory or on the storage card;
the sound can be played with ascending volume and in loops (i.e. as many times as you need);
vibration (requires hardware availability of the feature) can be set to work before or with the sound. Pulsation is customizable too.

Unlimited number of countdown timers. These timers are used to notify you when certain amount of time elapses. Countdown timers can have two time periods (second period starts after first period of time is complete). You can completely customize sound and vibro notifications for the timer (in the same way as for alarm). Settings of each countdown timer can be saved as a template for future use.
2 multi-stage timers that let you count time of some action and compare results of two attempts. You can use timer to fix intermediate results (for example when you run 5 laps, you can track time of each lap).
Skinnable clock with screensaver and hourly sound lets you have better control over your time.