Kleopatra - Kleopatra is a certificate manager and GUI for GnuPG.
Exocet - Exocet creates a Folder on your System.
OpenKeychain - OpenKeychain helps you communicate more privately and securely.
Kruptos - Lock and encrypt your photos, movies, files and folders using 256-bit file encryption.
Enigmail - Security extension to Mozilla Thunderbird and SeaMonkey
R-Crypto - R-Crypto is smart data security and disk encryption software that allows you to secure your sensitive information via strong encryption.