A number of Android apps have been found to be committing advertising fraud and have been kicked out of the Google Play Store by Google.
An advert earns the publisher money when it is clicked and costs the advertiser. What these Android apps were doing were simulating people tapping on adverts on their phone. If an advert was in an app, then the app publisher would earn money from these fake taps/clicks.
It is against the ad provider’s (Google’s) terms and conditions to click your own adverts. After all, you could spend all day tapping/clicking ads and earn lots of money without actually doing anything.
Many apps over the years have been banned for fake taps/clicks and this latest round of Play Store expulsions focuses on apps by DO Global and its subsidiaries. Apps include ES File Manager, Total Cleaner, Smart Cooler, and RAM master.
If you have these apps on your phone, you should delete them.