Syncdocs is a cloud-based backup and sync application that allows users to securely store and share files across multiple devices. With Syncdocs, you can easily back up your files to Google Drive, Dropbox, OneDrive, and other cloud storage services. It also allows you to sync your files across all of your devices, so you can access them from anywhere. It also provides enhanced security with two-factor authentication and file encryption for added security. Syncdocs also offers a free version for personal use, as well as an enterprise version for businesses.
FlowCloud discontinued due to storage and maintenance issues. Read more here: https://flowcloud.xyz/why.html
Discontinued Appears to be a dead link
Discontinued The program is no longer updated. The latest version, 0.9.5, released in May 2013, can still be downloaded from the Mac App Store.
You can actively synchronize multiple accounts simultaneously without the need to selectively switch accounts.