uber rider app

Does anyone know how to turn on tipping in the driver app and/or how to now in the app if it is turned on? I had a rider last week comment that I needed to turn on tipping. I have looked online and event sent Uber to support a message via on the site and Twitter and to no avail I got nothing...

anyone updated the Uber Rider app? My phone automatically updated it. It's a little sore on the eyes not as convienent for drivers to see where the others are. What do you guys think?