Wow, what a surprise! It looks like Facebook was the most-popular app of the year! Sarcasm aside, not only was Facebook the most-popular app of the year by a significant margin, Facebook Messenger came in third place behind YouTube, but still managed to be the fastest-growing app of the year, with a 31% increase in monthly active users over last year. This is all according to a report from Nielsen, which showed that Apple, Facebook, and Google are dominating the app world yet again, with Facebook, YouTube, Messenger, Google Search, Google Play, Google Maps, Gmail, Instagram, Apple Music, and Apple Maps taking the top ten spots, in that order.