Kleopatra - Kleopatra is a certificate manager and GUI for GnuPG.
GnuPG - GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP).
GPG4Win - GPG4Win is an encryption program for files and emails. The program encrypts emails and files so that they can only be read by those intended to receive them.
AES Crypt - AES Crypt is an advanced file encryption utility that integrates with the Windows shell or runs from the Linux command prompt to provide a simple, yet powerful, tool for encrypting files using the Advanced Encryption Standard (AES).
GPGTools - Use GPG Suite to encrypt, decrypt, sign and verify files or messages.
pep.security - Privacy by Default.