$240 million in customer purchases makes January 1, 2017 the App Store’s busiest day ever App developers earned $20 billion in 2016 — up 40 percent from 2015 Cupertino, California, 2017-Jan-09 — /EPR Retail News/ — Apple today (JANUARY 5, 2017) announced that the App Store welcomed 2017 with its busiest single day ever on…