The extension feature of Macube is to quickly scan different kinds of extensions on your Mac and enable you to freely manage them on Macube. By turning the unneeded plugins off, you can usually improve the speed of your Mac.
When Macube finishes scanning, you can check the results one by one, which are listed with name, created time, size, etc. If you tend to preview them or locate the files, click the magnifier icon next to the items to open the saving folder and view them.
Usually, applications can't access some important system files and user data for system restrictions on apps. The Helper Tool is used to get permission from the system, then Macube can remove some system caches or junks. You can go to Macube > Extensions > Proxy to disable this helper tool if you don't want it on your Mac.
I found some files stored older than one year and taken up more than 2 GB. The files are displayed repeatedly in > 100 MB and > 1 year. Thanks to Macube, I removed successfully.
My Macbook Pro informed me that the storage is getting full so I download Macube to clean up the junks files, especially the caches and localization which are unnecessary.
My Mac is a 128GB MacBook Air. Every gigabyte is important to me. So it is such a relief when Macube give me back 38.6 GB of storage from iTunes.