MacDropAny

“MacDropAny is the easiest way to sync any folder on your Mac with Drop Box, Google Drive, iCloudDrive, or SkyDrive. Using MacDropAny, you can have access to any folder on your computer, from anywhere in the world. Imagine being able to get to your Desktop, music collection, or Documents folder in an instant from wherever you are!” The main feature is having the ability to sync any folder on your computer with any of the aforementioned cloud storage providers.