Looks like the Google Earth Flight Simulator[0] didn't make the cut. Many features are missing from the original desktop app and it's not immediately clear what this offers over using "Earth" within Google Maps. The "auto-rotate around the landmark" feature is also a pain for people who are used to maps being north-facing by default.
[0] https://googlesystem.blogspot.co.uk/2007/08/google-earth-eas...