AR and VR capabilities are currently in private beta
(iOS and Android, with an older version for .NET Xamarin).
Sign up before the hackathon to get access to the SDK by emailing ArcGISRuntimeARVRBeta@esri.com.,
or we can send you an invitation at the hackathon.
If you're a developer who wants to build AR/VR apps like
the above, see this
technical session from our 2018 Developer Summit,
this 5
minute demo, and this video
showing an app being built.
The app I showed during the opening talks is available in source code here (you
will need to install the beta as described above).