Android users collectively spent $40,000 on an app that does nothing.

For $3.99, Virus Shield promised to protect your phone by scanning apps, settings, files and media for viruses in real time. All that without pesky advertisements or draining your battery.

It sounded too good to be true — and it was. But that didn’t stop 10,000 people from downloading it, making it the top-selling paid app among Google Play’s offerings for Android.

It got an impressive 4.7 star rating from users. To be fair, the app did do one thing reliably well: It could change the image of an “X” into a “check” after a single tap. Unfortunately that didn’t mean the app actually scanned and checked your phone, according to Michael Crider at Android Police.

Crider discovered all this and linked to the app’s code so that those familiar with computer code can check it out for themselves.

“This is fraud, pure and simple, and the developer ‘Deviant Solutions’ potentially made considerable amounts of money based on a complete lie,” Crider wrote.

It’s not the first time the Android Police have found fake apps in Google Play’s app store, but this was an especially egregious case.

“It’s somewhat disheartening that an app so obviously fake could rise to the top, especially considering that it’s paid, and possibly hundreds or thousands of people have been defrauded already,” Crider wrote.

But he was at a loss for a solution: “Any effective way of deterring outright fraudsters like this would go way beyond the basic filtering that Google is doing at the moment, and it would also make the Play Store less ‘open,’ if only marginally. That being said, it’s also clear that something needs to be done.”

Unlike Apple, Google doesn’t police the apps sold in its store. However, users can report suspicious apps and they will remove them.

Business Insider reported that Google took the app out of the store Monday morning.

In late March, TrendMicro found two Google Play apps, Songs and Prized, that were secretly mining cryptocurrencies on users’ phones to benefit those apps’ designers. This can cause problems for the phones, overheating them and shortening their life spans.

Both apps have also since been removed.