Ive been living in Shanghai for 5 months now.
WeChat is 125% necessary to function in todays China.
It is used daily at work by our teams to communicate and share updates in plae of email (american company). I order and pay for household items from TMALL and JD.com via wechat. I split checks, follow the news, communicate with friends, make haircut appointments all through the app. It really is one-size fits all.
If I were leading product at whatsapp, snapchat, facebook messenger..this would be my future roadmap for success.