Attention Walmart shoppers—you may now speed through checkout using your mobile app. That would be in one Toronto store where the giant retailer is trying a self-checkout system that uses the My Walmart mobile app. Walmart is no stranger to mobile self-checkout as all its Sam’s Club stores employ its successful Scan and Go smartphone app. Walmart tried this in selected U.S. stores, but then discontinued it. The Canadian version seems very straightforward and has highly visible signage in the initial store. Customer adoption and reaction will be worth watching. Amazon Go stores receive most of the headlines. But mobile app self-checkout systems present a very viable method for retail stores of all sizes. Lower installation costs and the opportunity to further engage customers via a mobile app are two good reasons.