If you’re hectic on privacy then you can trust Edward Snowden when he uses a messaging app. Signal is a free calling and messaging encrypted app from Open Whisper Systems. The app has been available for iOS since last year and is now available for Android users as well.
— Edward Snowden (@Snowden) November 2, 2015
Signal is the combination of TextSecure and RedPhone into one encrypted calling and messaging app for iOS and Android. Existing TextSecure and RedPhone users will be prompted to update the app to Signal which is now a conveniently combined communication app.
The creator of Signal,Open Whisper Systems’s, CEO Moxie Malinspike assured users that the messaging app will be as secure as ever, stating that:
As always, Signal uses your existing phone number and address book. There are no separate logins, usernames, passwords, or PINs to manage or lose. We cannot hear your conversations or see your messages, and no one else can either. Everything in Signal is always end-to-end encrypted, and painstakingly engineered in order to keep your communication safe.