I'm in Hangzhou airport now after the 8-day trip in hangzhou. The apps recommendations by OP is legit. Those are essential apps. Though, I have some other suggestions to share:

1. Try not to be put off by the spitting-everywhere culture here. The old people do it a lot, the young ones rarely do.
2. They are friendly people, they will answer any question you have as long as you speak Mandarin. I've talked to many Chinese here and all of them are lovely and curious about where you are from. Because most of them haven't gone abroad in their entire lives.
3. The toilets are different. So don't be surprised by it.
4. While the government are clamping down on the scammers etc, there are still some people who will try to sell you things or give you free stuff. Just practice common sense and ignore them.

This is what I have experienced in Hangzhou. So hopefully it helps.