PhoneLeash: SMS/MMS forwarding - PhoneLeash: SMS/MMS forwarding app offers features that let you forward your desired text messages and multimedia messages to your email or your other mobile phone so that you can access them later.
Kleopatra - Kleopatra is a certificate manager and GUI for GnuPG.
Easy Message - Easy Message app comes up with features to help users in effortlessly sending text messages to a phone number, which is not in the contact list.
OpenKeychain - OpenKeychain helps you communicate more privately and securely.
Cellcrypt - Cellcrypt app provides features so you can enjoy secure conference calling, messaging, and sharing of documents.
Enigmail - Security extension to Mozilla Thunderbird and SeaMonkey