Totally different requirements. Some countries' fast food apps are for mobile ordering and delivery, some are a giant collection of coupons, and some are only for nutritional information. And some are just for promotional activities (only used for various promotional calendars.) After seeing all the different APKs I tried out a few for different countries out of curiosity and at least for Burger King they were entirely different applications with completely different use cases. To cram them all into one global app would be an enormous mess.