Apple Inc.'s mobile payment system is coming to Canada but will be, at least initially, limited to holders of credit cards from American Express Co. Apple CEO Tim Cook, during a conference call Tuesday to discuss the company's fourth-quarter earnings, announced that Apple Pay would be in Canada and Australia this year for American Express customers, and Spain, Singapore and Hong Kong would follow next year. Apple Pay is currently operational only in the United States and United Kingdom. American Express said in a press release that the partnership would allow customers in Canada and...