Doh...meant to say and "stay on the LAN". Always open a tunnel/SSH for transfers out of network. I see they've got a SFTP as a pay app. Safer way to go I suspect.
I experimented with several different FTP-clients and had the most luck with BeFTP. It isn't anything marvelous, but it does work fine. You can download a limited version to see that it works. The actual functioning version cost 15 dollars or something, not too much. The limited version doesn't allow you top save the settings, and so it quickly gets old.