pep.security - Privacy by Default.
GNUPGK - A GnuPG Frontend GUI made in C#.
TheLetterEncrypter - TheLetterEncrypter is a small (14KB download) AES-based text-encryption program.
PGP Tool - PGPTool allows you to encrypt and decrypt files. It's free and easy to use.
CTI Text Encryption - CTI Text Encryption is an encryption tool that can encrypt any text from messages and articles to codes, etc.
GPGTools - Use GPG Suite to encrypt, decrypt, sign and verify files or messages.