This app was mentioned in 6 comments, with an average of 1.00 upvote
https://play.google.com/store/apps/details?id=team.apollo.gala360unity
Gala360 doesn't show 3D 360 photos yet,but it handles 8k 360 photos very well
Here is another App that seems not listed in Play Store in VR mode but worked with Daydream platform:
Gala360 for Daydream VR: https://play.google.com/store/apps/details?id=team.apollo.gala360unity
https://play.google.com/store/apps/details?id=team.apollo.gala360unity
Gala360, the top quality 360 photos virtual travel app:)
Our Gala360 is ready for Daydream. See the world in high resolution 360 photos and interesting storeis.
https://play.google.com/store/apps/details?id=team.apollo.gala360unity
https://play.google.com/store/apps/details?id=team.apollo.gala360unity
Try Gala360, it's a 360 photo app for Daydream, should be on the lower end of power consumption
Best quality 360 photos on DayDream https://play.google.com/store/apps/details?id=team.apollo.gala360unity