With CleanMyDrive you can maintain your removable drives using its built-in automated cleanup feature. To enable it insert your drive, click the lights on the left of it in the main CleanMyDrive menu and turn on the Keep It Clean From Junk On Unmount switch. Or you can check Clean All Drives Automatically in the Preferences Window.
CleanMyDrive only monitors the space on your removable drives and cleans them from service junk (such files as .DS_Store, .Spotlight, Thumbs.db, Resource forks and other useless system-generated data) and trashed files (when you simply remove files, they appear in the drive's local Trash). Thus, it is totally safe to use CleanMyDrive.
The Eject All command unmounts all your mounted drives at once. If you close your MacBook or send your Mac into sleep mode after that, you will be able to eject any of your drives and be sure they won't be corrupted.
CleanMyDrive can clean your thumb drives and USB media storages. If you want to clean hard drives as well, check out our all-in-one cleaning solution CleanMyMac.
CleanMyDrive shows your network drives in its main menu, but the app is unable to clean them up from junk.
CleanMyDrive shows your Time Machine drive in its main menu but is not able to clean it for integrity reasons.
No, CleanMyDrive does not monitor your drives when you don't see the icon in the OS X menu bar. But you still can enable the option in Preferences to launch CleanMyDrive automatically on startup.
CleanMyDrive erases useless files so that they could not be restored.
That is because the service junk is being generated by the system everytime you insert your removable drive into your Mac (or PC). That is why it is useful to clean your drives everytime on unmount.