MultCloud - Multiple Cloud Storage Manager: Migrate, move, sync, copy, backup and transfer cloud files with MultCloud, which supports Dropbox, Box, Google Drive, Mega, OneDrive and FTP, etc.

NetFinder - NetFinder - Award winning and very cool FTP/SFTP client with advanced website & general file management, automation, mirroring solution for Mac OS X with a Finder like interface.

Koofr - Koofr offers safe EU based cloud storage with free storage space for life and options to connect multiple cloud accounts (Dropbox, Google Drive, OneDrive) and your personal storages.

LAN-Share - LAN Share is a cross platform local area network file transfer application, built using Qt GUI...

odrive - odrive aggregates all cloud storage. Access, sync, share, and encrypt everything in one place. Integrations to 20+ storage services, desktop sync, Linux support, placeholder files, zero-knowledge-encryption, web client, advanced sharing, and more!

Meld - What is Meld? Meld is a visual diff and merge tool targeted at developers.