I use NSUserDefaults to save a switch on/off and so far it is good. It remembers the switch position in next session.
Now to the thing which I do not understand.
I use the same switch (with the same name)in another view, let´s say a flip view which is pushed in from the first view. If I change the switch in the first view it is automatically changed in the flip view.
But the other way round, if I change it in the flip view it is not changed in the first view when I go back. Only if I restart the application the first view is also changed.
How can I solve this to be changed at the same time? Or kind of refresh the first view without need to restart.
Your first view is not refreshed, as it is not initialized again. If you using ViewControllers you could update your switch in viewWillAppear (if isViewLoaded).