The Open Whisper Systems, which are well-known for their safe calls app RedPhone, have come up with a new one. This time we are talking about the free encrypted calls you can make on your iPhone all over the world. You do not have to guess twice the Signal app is fully compatible with the RedPhone.

This app is simple and safe to use. In addition, you do not have to worry about complicated passwords. Both you and your contact will get a pair of words. If these words match between the parties, who are communicating, you are good to go. If not, then there is someone uninvited trying to mess your things up.

The Signal runs the ZRTP, which is a security encryption protocol developed by Phil Zimmermann. He is also known as the father of the Pretty Good Privacy (PGP) system. On the other side, it is worth mentioning that the Signal is initially designed to be an open source platform.

The Open Whisper Systems have some ambitious plans with this one. In the next stage, they plan to include Signal’s version for the text messages, as well. Definitely some good news for iPhone users. We only hope that Apple will close all open backdoors first. You know what we mean with this one, don’t you?