A combination of photos show the faces photographed by photo-editing app Meitu of Facebook founder Mark Zuckerberg, Amazon founder Jeff Bezos and SpaceX founder Elon Musk (from left to right). [Photo/via Meitu]

6. Makeover apps

For its users, the photo app Meitu is an online version of plastic surgery. It allows them to enhance how they look: thinner, bigger eyes, no wrinkles, even skin tone.

And to its China-based developer and stockholders, Meitu is now valued at $4.26 billion with more than 456 million monthly active users.

Meitu, developed by Guangzhou-based photo sharing community and app maker POCO.CN in 2008, is most popular in China, one of the biggest and fastest growing beauty markets in the world.

Meitu's first photo editing app for the US market was Airbrush in 2015. Users can take the app's array of editing tools to remove blemishes and dark circles from the face, slim jaw lines, lengthen a face and figure, add anime-style makeup and brighten skin.

Meitu has also been rocking the Brazilian market for photo editing apps. Meitu arrived in Brazil last April. Since then, the company has launched translated versions of some of its main apps.

In the past year, the number of downloads of Meitu apps rose 840 percent, and Meitu reached 10 million users in Brazil.

Meitu said its app is used in 26 countries, with 430 million users outside of China. The company said its app has been installed on 1.1 billion devices and that its 456 million global monthly active users have generated 6 billion photos through its apps.