This app was mentioned in 5 comments, with an average of 4.80 upvotes
People commenting obviously didn't read OP's post. He is looking for a specific app that was demonstrated to him by a dude working at Google's. The app consists of photospheres available through a virtual museum.
EDIT : Orbulus might be what you're looking for.
I always show people when they come over, its fun. There is an app, orbulus that me and my friend took turns using when we were tripping one time...it was amazing.
You must be thinking of Orbulus.
Very cool. Similarly there's also Orbulus
Orbulus is my recommendation. It's like a mini-vacation with high-res 360 photos.
https://play.google.com/store/apps/details?id=com.VRCraftworks.Orbulus&hl=en