Most of the time everything functions perfectly, but there have been several times when the repeating alarm hasn't triggered.
I have been using this app for about one month, and for that time I have had one alarm set for 5:00 AM M-F. Usually everything is fine, but 2 or 3 times the alarm has not triggered. One time I had the mp3 player up (but it was not playing music). Another time I think the calendar was up. The last occurence happened this morning, and there where no other apps running in the foreground.
Based on the alarm clock UI everything was good to go.
The only way to confirm the alarm is to click the tiny OK botton. As you can imagine at 5:00 AM this is rather difficult, and my wife is often yelling at me to "shut that damn thing off" before I get my stylus out and peck the correct 15x20 pixel region on the screen. It would be nice if a large botton were provided on the bottom of the screen to confirm an alarm. Ideally the button would be design with finger tapping in mind.