According to data from Sensor Tower, Facebook was the top app publisher in the world for Q4 2018, with over 800 million app installations. It was also the number one publisher on Google Play, amassing nearly 700 million installs. The App Store champion publisher was Google, which managed close to 200 million installs for the quarter.
https://www.notebookcheck.net/Facebook-was-the-world-s-most-popular-app-publisher-in-Q4-2018.408371.0.html