Although Google has tightened app policies on the Play Store over the years, the company thinks it can do more to protect users. One way to do that is to crack down on the amount of malware and bad apps on its marketplace, so it's begun reviewing apps before they become available to download. The new policy, which is similar to Apple's approach on the App Store, has been in effect for a couple of months and uses a mix of algorithms and human intervention to weed out rogue apps.