The good or service being "mobile phones" or "mobile apps" -- e.g. the whole market they belong to.
Not "iPhones" or "iOS apps".
Any company has "pricing power" over their own products and marketplace.
>Having less than 50% share in some market using the market boundaries usually drawn by analysts does not prove or imply the absence of pricing power.
No, it just makes it irrelevant as to the law.
No, it doesn't work that way. If you have pricing power on, say, iPhones -- you can raise the price and sales don't move to someone else -- you have a monopoly because price power demonstrates that whatever putative competitors exist are in a functionally separate market, not substitute products in the same market.
> Any company has "pricing power" over their own products and marketplace.
No, companies in competitive markets lose sales to competitors when they raise prices, which is exactly what pricing power means doesn't happen.
You are a monopoly when you have pricing power over some good or service (the ability, in some range, to raise prices without losing sales to a competitor). Having less than 50% share in some market using the market boundaries usually drawn by analysts does not prove or imply the absence of pricing power.