This package contains 7 skybox materials for dawn, day, fog, sunset and night. Each material is made from 6 skycube textures (6 x 2k squared).
You can buy this package at:
https://www.assetstore.unity3d.com/en/#!/content/91122
Sky Cube Materials Set
Hello.
Is this material set use on mobile device?
LikenLiken
Yes, it can be used on any target platform.
LikenLiken