skype is good for making phone calls to overseas numbers voip service is pretty good. It's pretty normal if you use it to chat with ppl with skype app. I think many china ppl use skype to call their friends back home. Their world service is pretty good. Unlimited calls to quite a number of countries. Viber seems to be less in use more ppl using tango, line instead. You cannot make phone calls on whatsapp. Wechat is used to chat with strangers and many hookers use them too just ask alamaking.