BoxCryptor - Boxcryptor encrypts your sensitive files before uploading them to cloud storage services like Dropbox, Google Drive, Microsoft OneDrive, Box, and many others.
GnuPG - GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP).
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
GPG Suite - Use GPG Suite to encrypt, decrypt, sign and verify files or messages.
Cryptomator - When it comes to saving your files on a cloud server, it is important to ensure the security of those files. Keeping your delicate files out of the wrong hands can save you a lot of time and hassle. Read more about Cryptomator.
Autocrypt - Convenient End-to-End Encryption for E-Mail