Surprise announcement! In the middle of the Fallout 4 segment, Bethesda announced a mobile game called Fallout Shelter, and it has already been released. They mentioned that this game is to be based off of an old game called Progress Quest. This game is going to have a Sims/Pocket God like feel, with you playing the role of Overseer. You can number your Vault as you see fit and delve into the lives of your vault occupants. You can manage your resources, train the occupants, and even send them into the wasteland to gather materials. Note that accidents and raids can also happen. So this isn’t so simple as starting it up and walking away.
This game is free to play, will have no paywall, and needs absolutely no internet connection. As far as we know, this game is only being released on iOS, but it could very well reach out to other mobile platforms in coming months.