RaiDrive is a cloud file manager that supports Google Drive, Box, etc

Cryptomator is a multi-platform transparent client-side encryption of your files in the cloud.

Air Explorer is a software to manage all your multiple cloud drives (like Dropbox, Onedrive, Google Drive, Mega, Mediafire, Box, Hidrive, Yandex, Baidu, etc.

PDF Studio is a multi-platform PDF editor.

odrive is a Universal sync client to unify, sync, share, and encrypt all your files in Amazon Cloud Drive, Dropbox, Google Drive, OneDrive, Box, S3, WebDAV, F…

Boxcryptor protects your data in the cloud with end-to-end encryption.