Solo travelers who have been to China: what was the hardest part?

I recently took a friend to China and ended up realizing how much harder the trip can be when you do not have a local with you.

A lot of things I take for granted — paying for things, using the right apps, ordering food, taking trains and dealing with QR codes — became surprisingly confusing. Whenever something came up, my friend would just ask me what to do. It made me wonder what the experience is like for people traveling to China completely on their own.

I prefer traveling independently over joining a tour group. I like having the freedom to change plans and explore at my own pace, and I imagine a lot of solo travelers feel the same way.

I am working on a small app for first-time visitors to China, especially solo travelers, but I do not want to build features only around what I think travelers need.

If you have traveled to China solo, or are planning to, what was the most frustrating, confusing or stressful part of the trip? If an app could have helped with one thing, what would you have wanted it to do?

I would love to hear any experiences, even the small annoying things.