BoxCryptor - Boxcryptor encrypts your sensitive files before uploading them to cloud storage services like Dropbox, Google Drive, Microsoft OneDrive, Box, and many others.
Wise Folder Hider - Wise Folder Hider is a free file/folder hiding tool.
Mega - Secure File Storage and collaboration
Folder Lock - Folder Lock is a security software that helps you to password protect files, shred files, clean history, encrypt the personal documents and much more.
Google Drive - Access and sync your files anywhere
My Lockbox - My Lockbox is a security software enabling you to password protect any folder on your computer.