Dropbox - Online Sync and File Sharing
SpiderOak - SpiderOak makes it possible for you to privately store, sync, share & access your data from everywhere.
Box - Box offers secure content management and collaboration for individuals, teams and businesses, enabling secure file sharing and access to your files online.
Filestash - Filestash is a modern client for FTP, SFTP, S3, WebDAV, Minio,...
Microsoft OneDrive - Secure access, sharing & file storage
CM Transfer - CM Transfer – Share Any Files with Friends Nearby is a free to use mobile application that comes with the beautifully redesigned new look and enhanced file transferring technology that makes the sharing of files faster, simple, and secure.