Alarm Clock Plus is built from the stock android alarm clock app for 100% reliability. Features include but are not limited to the following:

Unlimited alarms, optionally require a math problem to be solved for dismiss and/or snooze, set number of problems to solve, 5 math levels, FADE-IN alarm (Alarm Volume will gradually increase), app alarm (wake up to pandora for example), music alarm, disable snooze, launch any app when power connected, all stock features, plus much more!