I should add that I tried MyAlarm first before Mobylo's Multi-Alarm. I did not have firewall issues (since I leave mine off) and it worked great.

However, at the time (and perhaps this has changed now), MyAlarm did not autostart on phone reboot. So that is the main #1 reason I went for Mobylo's alarm application. Perhaps someone can confirm/deny that MyAlarm is signed and/or can autostart now, in case that factors into someone's decision in the future.