At QuakeCon 2015, Bethesda has announced that Fallout Shelter will be coming to android on August 13th which is in line with the previous Twitter thread from Todd Howard. Along with the release on Android the game is being updated with new features to include new attacks and enemies. Deathclaws to fight and Mr.Handy to help gather resources.
We are going to support Fallout Shelter for a long time. This is something we did on the side and we were blown away by the response.
– Todd Howard, Bethesda
Fallout Shelter was announced during E3 2015 as part of the Fallout 4 reveal and is available now for iOS.