Cloud storage providers like Dropbox, SugarSync, and Google Drive all have free apps available in the Play Store, but none of these sync up with folders saved on your Android device's internal memory the way their desktop clients do. For that functionality, look no further than FolderSync. This aptly named app can sync folders with over ten different cloud storage services, and version 2.5 adds another option, Copy.com, to the list.
Alright, control freaks (otherwise known as "my people"), this one's for you. FolderSync is a fantastic little app we've just discovered that lets users sync folders between local storage and a number of online storage services. The app supports one- or two-way sync and provides a host of settings to tweak the app to all your sync needs.
Sync can be done on a schedule or when a folder changes.