For hosting common files it's ok. Also it is on Android too do, great to transfer files between your Windows and your phone. But if you want better security you have to subscribe a monthly offer.
Dropbox - Online Sync and File Sharing
Filestash - Filestash is a modern client for FTP, SFTP, S3, WebDAV, Minio,...
Google Drive - Access and sync your files anywhere
Syncany - Syncany is an open-source cloud storage and filesharing application.
Mega - Secure File Storage and collaboration
FTPSync.pl - FTPSync.pl is a PERL skript to synchronize a local directory tree and a remote FTP directory tree.