CryptUp is the simplest PGP application for Gmail. This application makes it extremely easy to create encrypted email within Gmail. There’s no need to understand how PGP works. CryptUp just works.

CryptUp adds a new button in Gmail called SECURE COMPOSE. It lets you send encrypted emails to anyone. Just click on in, write your message, and send it

CryptUp is available for Chrome, Firefox an Android soon. The Chrome extension is installed directly for the Web Store. The Firefox plugin however must be installed manually.