I noticed literally anyone in China with a cell phone had their WeChat app. Our daughter used it exclusively to video chat with us back here in the states. Was far superior to Skype or Apple FaceTime.
I have an assortment of apps that I use, this is from highest to lowest:
Whatsapp - mostly text, sometimes for calls. the majority of friends have it as well as some of my family
WeChat - My Wife is Chinese and we do not live in the same country, so we mostly use this
Line - a couple of friends are here and not using other apps
Viber - it works well for a few friends and sometimes also use to call my wife
Skype - I keep credit on skpye so use it to dial phone numbers in the US if I need to as I am mostly never in the US
iMessage/phone text - mostly to retrieve a log in code for bank or website
Facetime - only used it once to make an audio call to a friend that had no other apps installed.
FB messenger sucks and I don’t have FB installed on my phone.