How does Uber achieve this UI in WatchKit?
The way Uber (and most of the big companies' UIs) is that they just generate an image in iOS, which is sent back to WatchKit extensions and just rendered as an image.
If you want to build your user interface with the current SDK version, this is the only way to achieve exactly what you want. You will need some hacks to achieve interactivity, but you should be able to do it yourself :)
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