Security issues are very important for all users of any service, both on mobile devices and on computers, and as Apple fights the FBI the ProtonMail, an application that promises to encrypt your emails giving users greater security.
Created by a startup from Europe and available on the web, on iOS and also for Android the software is completely free and uses PGP encryption end-to-end, which encrypts the data even before the message is actually sent. This ensures complete data privacy, and that nothing leaves your device before being properly encrypted.
If you want to get even more security for your emails, ProtonMail is highly recommended, "ensuring your right to privacy, making sure your messages fall into the right hands, not government inspections," as founder Andy Yen pinned in the post service launch.
To further increase trust in service and encryption end-to-end, the developers opened the code for the service's web interface and promise to do the same for the applications. Going through a crowdfunding campaign (crowdfunding) in 2014 and raising more than half a million dollars, the service already has more than 1 million users, and with routine cases on security and privacy the tendency to increase this number is even greater.
If you want to exchange emails with complete security, a great tip. The accounts created in the service can be @ protonmail or @ protonmail.ch, the choice of each one.