(Though it is fully function)
SyncIt is a basically a Dropbox extention, it uses the Dropbox API and your Dropbox Account to keep any specified file updated in you Dropbox as well as on any other Android devices with SyncIt installed.
What this means is say you have to have a certain game always up to date on all of your android devices? Well simply select it in SyncIt and have it installed on both devices and SyncIt will monitor that file and keep it up to date on both devices.
*** How To Use ***
Device 1 - Simply use the built in file explorer to select any file or folder(Pro) you wish to sync. They will automatically be uploaded as the files are updated. If you wish to add another device first go and long-press the given file/folder and click "Backup" for all of our files/folders listed.
Device 2-Ect - Simply login to, the files will be downloaded. Then go long press each file/folder and click "Restore". Once done for each file/folder you are ready to go. This is a one time process.