Encrypted mail & calendar app
Please note this is still BETA version and it might not be completely stable. p≡p is a cyber security solution which protects the confidentiality and reliability of communications for citizens, for public offices and for enterprises. It provides end-to-end cryptography in all common crypto-standards through the app that you install on your phone.
Walnut is Simple to Install, configure and use application that provides End to End Person to Person Security and protect any IMAP/ SMTP based Email accounts using a unified client interface.
Mail1Click is a free a secure mail service that uses strong encryption to keep your communications safe.