You want every app of yours to be a different "user" so they can't access each other's data without arbitration. The term "user" is an unfortunate Unix inherita

You want every app of yours to be a different "user" so they can't access each other's data without arbitration. The term "user" is an unfortunate Unix inheritance. There's no reason that a single human (as he might on Unixes like Android or iOS) shouldn't have a hundred Unix "user" IDs at his disposal, one for each app.