Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.
GnuPG - GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP).
iGPMail - iPGMail: OpenPGP Email security for iPhone and iPad
Kleopatra - Kleopatra is a certificate manager and GUI for GnuPG.
jCardSim - jCardSim is an open source simulator implements Java Card, v.2.2.1: - javacard.framework.*
PGP Tool - PGPTool allows you to encrypt and decrypt files. It's free and easy to use.