An example of an 'app which can look at your list' is Springboard, the iOS internal name for the GUI with home screen and so on. Another example is of course Sy

An example of an 'app which can look at your list' is Springboard, the iOS internal name for the GUI with home screen and so on. Another example is of course System Preferences. I don't believe Apple ships any optional apps which have this level of privilege, let alone one which doesn't obviously need to have it. This is possible, but to the best of my knowledge it isn't the case.