[Crunchyhippo]

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.

[UJ95x]

I'm assuming you mean notifications. Open the app, hit the menu button on your phone, and click settings. There is an option to turn off sounds.

[Golfdriver97]

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.

https://play.google.com/store/apps/details?id=com.nightskeeper

[Bosbouer]

The built-in blocking mode works a treat. You can allow "favourites" phone calls through and block all else for a set period of time.