Marking the biggest week of the year for mobile games, research firm Sensor Tower reports that sales of game apps between Christmas and New Year’s Day jumped 53 percent over the same period last year. “Smartphone and tablet users spent a record $967.6 million on game apps for iOS and Android devices,” notes The Wall Street Journal. “Two factors typically goose spending during the week: mobile devices given as gifts, and people off from work and school who have free time to load up on apps.” Additionally, game developers typically introduce “discounts and special holiday-timed events during the week.” According to Newzoo, mobile is now the largest slice of the $100 billion video game pie.