Fly is essentially Google Earth VR running standalone on Meta Quest headsets and Apple Vision Pro.
On Quest Fly joins EarthQuest, another app with the same pitch. On Apple Vision Pro, it's the first time you can get the Google Earth VR experience on-device.
Both apps use Google's new Photorealistic 3D Tiles API for 3D terrain and buildings, with a lower peak quality compared to the official Google Earth VR. The biggest difference, though, is that Fly and EarthQuest run on the headsets themselves, not requiring a PC.
As with the official Google Earth VR and EarthQuest, you can travel anywhere on the planet, and you'll find 3D geometry in most cities and landmark areas.
By default, Fly places you on the inside of a giant drone with a rather strange locomotion system where you lean or move your body relative to the center of your playspace to traverse horizontally. This can be changed to the left thumbstick in the settings for more traditional controls, and you can also disable the drone model for unobscured viewing of the landscape.
What you won't find in Fly though is Google Street View, the ability to launch into 360-degree immersive images captured from positions along most streets on the planet. This is a key feature of the official Google Earth VR, and is also available in EarthQuest.
Fly is available for $10 on the Meta Quest Store or $15 on the visionOS App Store. Alternatively, EarthQuest is available for $9 on the Meta Quest Store.