Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
iGPMail - iPGMail: OpenPGP Email security for iPhone and iPad
Easy File Locker - Easy File Locker is a pretty small file at 224KB and will do exactly what it says.
jCardSim - jCardSim is an open source simulator implements Java Card, v.2.2.1: - javacard.framework.*
GnuPG - GnuPG is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP).