I still can't believe HOW BAD this app registration process is. We failed to register at home, twice, because of a ridiculous "security check". They are asking you to scan your QR code from a chinese person. So we found a chinese person, but it failed, because they are only allowed to do this once per month. So we came to china, needed to get a mainland china phone number including registration of our passport. Found another chinese person to scan that ridiculous qr code, then sending/receiving SMS failed. - This app is a big piece of something. As opposed to claims on some websites, we never needed wechat or wechat pay, could do everything we wanted without it, any person claiming this app is a MUST have for tourists is spreading nonsense in my opinion. I'd rather skip China as a tourist than having to deal with this app. Fortunately, we never missed it.