In the Clock app, if I use a timer or alarm that goes off while my iPhone is on vibrate mode, the alarm sound still goes off. Is there a way to make it obey the vibrate mode? Or a way to tell it whether or not to ignore it?
Create a silent ringtone (e.g. a short piece of silence in Garage Band or the ringtone creator of your choice) and set that as the sound for the alarm.