Google has released a blog post explaining why nearly 600 apps have just been removed from Android's Play Store. These apps were deemed guilty of "mobile ad fraud", which contravenes the Mountain View giant's policies. The apps in question include all those associated with the company Cheetah Mobile.
https://www.notebookcheck.net/Google-announces-the-removal-of-about-600-apps-from-the-Play-Store.455215.0.html
Cheaters Mobile. Well done, Google!