Scroll through Tam Jai International’s mobile apps and you will encounter a wave of perks, menu offerings and other choices laid out to tempt you to the Hong Kong restaurant group’s staple offering, noodles. The apps are among several strategies, along with filling all dining segments from breakfast, lunch, tea and dinner with new menu items, that the chain has introduced in the past few months to win back diners who continue to cross the border in droves for leisure and dining. Ronald Wong...