Hi, I have never used Uber before... how much do you tip?
You don't need to. It's set up to be cashless. No tips and you know the fare ahead of time. That's why it's awesome!
Please also know that you MAY have issues getting picked up using Uber - I know the hotels don't allow (how they track or if they track I don't know) but they noted to me that they don't allow Uber on property.
I have a friend who drives for Uber and for Lyft. Lyft allows customers to add a tip on the app, but Uber does not. So Uber doesn't require one to tip. My friend tells me that she doesn't necessarily expect a tip herself but that she is always pleasantly surprised when someone does. However, there are some Uber drivers that do expect tips and they have been known to give passengers a low rating if they don't tip.