With Cryptomator, the key to your data is in your hands. Cryptomator encrypts your data quickly and easily. Afterwards you upload them protected to your favorite cloud service.

Official website: https://cryptomator.org/

Bitwarden

https://github.com/purejava/cryptomator-bitwarden 

Plug-in for Cryptomator to store vault passwords in Bitwarden Secrets Manager

GnuPG

https://github.com/jht5945/gnupg-cryptomator 

Plug-in for Cryptomator to store vault passwords with GnuPG encryption

KeypassXC

https://github.com/purejava/keepassxc-cryptomator 

Plug-in for Cryptomator to store vault passwords in KeePassXC Usage Wiki

tiny-encrypt

https://github.com/jht5945/tinyencrypt-cryptomator 

Plug-in for Cryptomator to store vault passwords with tiny-encrypt encryption

https://cyberduck.io/ - Cyberduck | Libre server and cloud storage browser for Mac and Windows with support for FTP, SFTP, WebDAV, Amazon S3, OpenStack Swift, Backblaze B2, Microsoft Azure & OneDrive, Google Drive and Dropbox

Boxcryptor - https://www.boxcryptor.com/