If you are using Unity and developing an Early Access title, there is no excuse not to use Unity Analytics.
The tool is free, build-in and it only takes a few clicks to enable.
This works for both desktop (HTC Vive, Oculus Rift) and mobile (GearVR, DayDream) Unity virtual reality projects.
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What are your users doing while in Virtual Reality?
Time to find out and make them happy! :-)