I have been running Resilio Sync [1] (formerly BitTorrent Sync) for a while now, it also supports an 'encrypted peer' and has support for all the major platforms.
I also use Resilio Sync for distributing backups with encrypted peers, but I use Borg to backup into the folder for compression, de-duplication, and really easy PIT recovery. I've also added rdiff-backup on one of the encrypted peers in case the write host gets hit with ransomware and the backup overwritten.
[1] https://www.resilio.com