I go to China often but it's been two years now. I don't look forward to the next visit for this very reason—I'll need this to pay for any and everything. I'm not going back.
Cash still works exactly the way it always has, (almost) nobody is going to turn down your business because you don't pay by an app.
I was able to install and use it just fine. The problem was that it is impossible to link a non-PRC payment method to it. The same is true for WeChat Pay or Alipay—you've got to use a Chinese bank account or card as a source. I was not able to find a way around this despite over an hour of experimenting with the apps.
In contrast, it was easy to get taxis in Wenzhou. The drivers all initially asked for electronic payment, though, so it's probably only a matter of regulation that is preventing them from going cashless.