I can't find the setting to stop Facebook from announcing new posts by "pinging" me, which drives me crazy since the phone stays by my bed. I can't turn the volume down too low since I need to hear it ring in case my sick relatives call.
If the thing is to keep everything silent at night, I use Nightskeeper. That has a setting to allow contacts to come through (the whitelist settings).
From the app: Nights Keeper blocks all calls, but “white list” contacts will be able to go through. You can specify separate contacts or groups in your exceptions list.