Facebook is comfortably the top app in the United States with more than 115 million unique visitors in June 2014, over 30 million more than second-placed YouTube.
comScore tracked the 25 most popular apps amongst adults in the U.S., measuring both iOS and Android, and found that 115.4 million people had used the Facebook app in June of this year. 83.4 million had used YouTube, and other Google properties (Play, Search, Maps and Gmail) also featured in the top 10.
Of note: Pandora is massive (69 million visitors in June), Instagram (46.6 million) is bigger than Apple Maps (42.1 million) and Twitter (34.7 million) is less popular than Yahoo Weather (36.1 million). Also, no games, no WhatsApp and no Spotify in this list.