Is there a way to set off an alarm or make an audible notification when I receive a text message only from a certain number? I like to keep my notifications on vibrate while I sleep, but my district sends important notifications out sometimes in the middle of the night when I'm still asleep, so I'm not likely to notice the vibration.
Kinda. If you go to your sound settings and change the default text tone to "none" and then go to your contacts and change the text tone for whichever contact you want a notification from to something that DOES have sound, you will only get audible text alerts from that specific contact.
However this will not work if the phone is muted, or if Do-Not-Disturb is enabled.
I just tested this theory and it works. Hope that helps! ;-)
You could make the contact as a favorite and set the 'do not disturb', so only favorited contacts can call you etc.