360 Security is one of the most popular and highly rated antivirus Android apps available right now with over 100 million downloads and 10 million ratings resulting in a 4.6 overall rating. That’s pretty good. This antivirus and anti-malware app comes with a ton of features, including the ability to scan your device files for malware, scan your apps and games, enable real-time protection, and even comes with an anti-theft feature. You can also use the app’s built in cleaner and booster service if you want, but the validity of those types of features aren’t particularly substantiated. Perhaps the most useful feature for this one is an app lock that lets you password protect any app on your device which is great for keeping nosy people away. The best part? It’s completely and totally free.