What are some alternatives?
When comparing Cloudu and FlowCloud, you can also consider the following products
Filestash - Filestash is a modern client for FTP, SFTP, S3, WebDAV, Minio,...
Dropbox - Online Sync and File Sharing
Google Drive - Access and sync your files anywhere
Syncany - Syncany is an open-source cloud storage and filesharing application.
Box - Box offers secure content management and collaboration for individuals, teams and businesses, enabling secure file sharing and access to your files online.
ownCloud - ownCloud is an open source project enabling businesses to host their own cloud storage while maintaining regulatory and compliance needs.