lsyncd is described as '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' and is an app in the backup & sync category. There are more than 50 alternatives to lsyncd for a variety of platforms, including Windows, Mac, Linux, Android and iPhone apps. The best lsyncd alternative is Syncthing, which is both free and Open Source. Other great apps like lsyncd are FreeFileSync, rsync, GoodSync and Unison File Synchronizer.