BoxCryptor - Boxcryptor encrypts your sensitive files before uploading them to cloud storage services like Dropbox, Google Drive, Microsoft OneDrive, Box, and many others.
Internxt - Store your files in total privacy
Mega - Secure File Storage and collaboration
Files App - Files is a beautiful single-file PHP file browser and manager that can be dropped into any dir on your server, instantly creating a gallery of files and folders.
Cloudfogger - Easy and secure encryption for the cloud. Provides security for all cloud storage services like Dropbox, OneDrive and Google Drive.
Filen - Next Generation end-to-end encrypted cloud storage. Get started with 10 GB of free space.