We use groupchat in WhatsApp. Two separate groups, one for each side of the family. Works ok but I can kinda begin to see the benefit of snapchat's ephemeral attitude even though I haven't tried it myself. However I don't se my wife's mother wanting to switch. She's retired and finds a great deal of joy of revisiting old movies of the kids. She would want to save the snaps anyways but I guess you can do that?