Some were even fake apps designed to harvest user data! Most of the free Android antivirus apps I tested were ineffective against malware, filled with annoying ads, or falsely advertised as free - a lot of “free” apps are really just free trials or very limited versions of the premium apps. I tested all of the free antivirus apps in the Google Play Store - after weeks of testing, I only found a few products which I’m confident can keep Androids well-protected against malware.