QQ is an app created by Chinese tech conglomerate Tencent. The app offers Facebook Messenger-style instant messaging, along with online games, music, shopping, and more.
9. WeChat
2/10
Tencent's WeChat app is capable of messaging, social media, and mobile payments. As of March 2018, WeChat had more than 1 billion monthly active users.
8. Skype
3/10
Skype, which Microsoft bought for $8.5 billion in 2012, has been downloaded over a billion times on smartphones. The app got a face lift in 2017, which has helped it better compete with the likes of Apple's FaceTime and Facebook Messenger.
7. Snapchat
4/10
Snapchat launched on the App Store as Picaboo in 2011, and is now one of the most popular apps of all time. As of February, Snapchat had 191 million daily users.
YouTube is the most popular of Google's iPhone apps. The video platform is also consistently the top free iPhone app in the App Store, and is the third most-popular app of all time.
2. Facebook Messenger
9/10
Facebook's Messenger app is a messaging app spun out of Facebook's in-app chat service. The app has become immensely popular, and is consistently near the top of the App Store's free apps chart.