BoxCryptor - Boxcryptor encrypts your sensitive files before uploading them to cloud storage services like Dropbox, Google Drive, Microsoft OneDrive, Box, and many others.
AWS Transfer for SFTP - AWS Transfer for SFTP (AWS SFTP), is a fully managed service hosted in AWS that enables transfer of files over the Secure Shell (SSH) File Transfer Protocol directly in and out of Amazon S3.
Cloudfogger - Easy and secure encryption for the cloud. Provides security for all cloud storage services like Dropbox, OneDrive and Google Drive.
CompleteFTP by EnterpriseDT - CompleteFTP is a secure FTPS and SFTP server for Windows.
Mega - Secure File Storage and collaboration
SolarWinds Serv-U - SolarWinds Serv-U is a web-based, secure file transfer solution.