That's a monopoly but it's not an economy monopoly. You have a monopoly over where you live, but that's not an economic monopoly. Monopoly is not a magic word. The FTC has very strict standards for when something is considered a monopoly. It's not the same as the general definition.
Well, sure, they have control over their own platform. Monopolies are about markets though, and Apple is hardly a monopoly in the smart device app market.