My son recommended me this new iOS game yesterday.
Fallout Shelter by Bethesda
I tried it out and found that it is an interesting mash-up between Sims and Tiny Tower, two games of which I have enjoyed very much - and so...I'm stuck with it now, playing hours on end to expand the vault and to make sure the dwellers are happy, working, growing and contented.
The little simple (and useless) things that keeps me busy and occupied. But I think I've wasted too much time on it.