The most downloaded iPhone app in the world right now is one you've probably never heard of

Founded by Chinese internet giant Baidu, iQiyi is a YouTube-style video streaming app. The company claims there are 481 million iQiyi users and that people are spending 5.6 billion hours on the app every month, according to TechCrunch.

During the first quarter, iQiyi had an estimated 22.6 million downloads.

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.

QQ was downloaded an estimated 22.6 million times in the first quarter of 2018.

Tencent's WeChat app was also among the most downloaded apps last quarter with an estimated 28.9 million downloads worldwide.

WeChat is capable of messaging, social media, and mobile payments. As of March 2018, WeChat had more than 1 billion monthly active users.

Despite its tumultuous 2018 thus far, Facebook remains one of the top iPhone apps in the world. The app is perennially a top-10 app in the App Store, and was downloaded an estimated 29.4 million times during the first quarter.

Instagram is the most popular app in Facebook's lineup. The app is the second-most popular free app in the App Store and was downloaded an estimated 31 million times in the first three months of the year.

Facebook's Messenger app is the third-most popular free app in the App Store and had an estimated 31.3 million downloads in the first quarter of 2018.

WhatsApp, the encrypted messaging service that Facebook bought in 2014, has 1.5 billion monthly users. Last quarter, the app was downloaded an estimated 33.8 million times.

Google-owned video platform YouTube is consistently the top free iPhone app in the App Store. In the first quarter of the year, YouTube had an estimated 35.3 million downloads.

Known as Douyin in China, Tik Tok is a music video and social media app. The app lets you shoot and edit short clips, then add music and special effects to them. Tik Tok is owned by the same parent company that bought social video app Musical.ly for $1 billion last year.

According to Sensor Tower, Tik Tok has become a "total phenomenon" in China in recent months. In the first quarter of 2018, the app was downloaded an estimated 45.8 million times.