G-Alarm is a finger-friendly and reliable alarm clock for Windows Mobile. Better than Klaxon v2.0 that I have mentioned before. It is created by ageye and v1.5.1 was the last free version. You need to pay for v2.0 onwards.
The latest G-Alarm v2.5 has lot of enhancements compare to v1.5.1. However, v1.5.1 does its job well for me. It can wait me up and no minor issue (alarm disabled but still got reminder) that I face with Klaxon v2.0.
Download free G-Alarm v1.5.1 here or buy v2.x here.