Which smartphone apps topped the rankings in 2015? According to new data from research firm Nielsen, Facebook and Google dominated yet again. Facebook’s core app took the top spot on Nielsen’s list with 126 million unique users per month, followed by YouTube with 97 million, Facebook Messenger with 96 million, and Google Search with 95 million. Messenger experienced meteoric growth over the past 12 months, enjoying a year-over-year user increase of 31 percent; Apple Music (which ranked ninth in overall user count) came in just behind with 26 percent growth. “Smartphone penetration grew to 80 percent of U.S. mobile subscribers at the end of September 2015 from 78 percent at the start of the year,” read Nielsen’s note accompanying the data. “In third-quarter 2015, a majority of subscribers used Android (53 percent) and iOS (43 percent) devices to access their apps.” A mere three percent of users relied on a Windows Phone, while a miniscule 0.7 percent used a BlackBerry. Tech pros scanning the list will note that only Facebook (with the Facebook app, Facebook Messenger, and Instagram), Google (YouTube, Google Search, Google Play, Google Maps, and Gmail), and Apple (Apple Music, Apple Maps) made the top-ten list. This is partially a consequence of the mobile world essentially becoming a duopoly between Google Android and Apple’s iOS, meaning that the core apps produced by those companies are always front-and-center (and thus always in use) for the majority of mobile users. While Facebook also dominates, thanks in large part to the ubiquity of its social network, the company is notable for some app misfires, including Paper and Facebook Home. Not every piece of mobile software launched by the biggest tech companies succeeds; but their respective reach and resources ensures that even their weakest-performing apps receive a vital burst of publicity at the outset. For everyone else who works in mobile apps—especially the developers who create everything from productivity apps to games—this list must seem a little disheartening. But never fear: the mobile arena is huge and only growing bigger, meaning there’s more than enough room for everyone to try and make an impact.