Apple has a dominance in iOS, since it is their OS, but they don't have a monopoly in the world since only about 30% of mobile devices are iOS devices. Thus no

Apple has a dominance in iOS, since it is their OS, but they don't have a monopoly in the world since only about 30% of mobile devices are iOS devices. Thus no special case required. When iTunes was around there were other options for purchasing music, hence no monopoly.