Get Zello. It’s free and you can create a channel for your family.
If you lose wi-fi and cell data it won’t work though.
“If you lose wi-fi and cell data it won’t work though.”
That’s not a reason to get it then. If I have cell I can call/txt, I can also call/txt to my fam with wi-fi.
You gotta train your family how to get by in the times you can’t communicate.