Cleaner as it’s the best Mac Memory and Disk Space Cleaner in the App Store. After you upgrade your system, these apps may fail to start or even make the entire system crash. Also, apps outside the App Store cannot provide a quick update when a new macOS is released. Once you download apps from unknown websites or unidentified developers outside the App Store, there is a big risk that these apps may carry Trojan, viruses, or adware. However, do not simply believe that there are no viruses or adware found on the macOS. Cleaner?” This is a common question that many people want to ask as there were too many cleanup apps for the Mac and many don’t know which one is the best one or safe to use. We’re aware of a recent scrutiny of some of our Mac App Store apps and wanted to address it.