arRsync is described as 'Mac OS X frontend for the utility rsync . It is intended to provide a simple interface to a powerful backup and synchronisation tool. It is quite limited but it can already performed basic backups' and is an app in the Backup & Sync category. There are six alternatives to arRsync for a variety of platforms, including Mac, Windows, Linux, BSD and Cygwin. The best alternative is rsync, which is both free and Open Source. Other great apps like arRsync are Truck - Rsync Client (Paid), RsyncOSX (Free, Open Source), MirrorFolder (Paid) and lsyncd (Free, Open Source).
A graphical user interface for rsync, which looks-and-feels like a standard FTP client, but uses the rsync protocol ‘under the hood’ to boost transfer speeds. In technical terms, it’s an SSH browser with an rsync transfer engine.
Lsyncd watches a local directory trees event monitor interface (inotify or fsevents). It aggregates and combines events for a few seconds and then spawns one (or more) process(es) to synchronize the changes. By default this is rsync.