DroboSync for 5N

Why is there no Drobo Sync for 5N? I am currently using 2 5Ns in one office & would love to get two more 5Ns for an offsite backup.

I understand crashplan can be used but it seems to be a bit complicated to install until I get more linux literate.

A google search produced SmartSync for Site-to-Site Synchronization which got me excited for a second until I realized that I would have to install the software on a PC & not on the 5N itself.

BitTorrent Sync is also available as a DroboApp