Signal, formed through a merger of RedPhone and TextSecure, is the flagship app of the Signal Foundation, a non-profit dedicated to open-source privacy technology. The software which underpins the Signal app has been imported onto WhatsApp, Facebook Messenger, Skype and Google Allo, although end-to-end encryption is not offered by default on these platforms. It launched the Signal app in 2015 for iOS, Android and desktop, which came with end-to-end encrypted messaging. Signal has since added ...| Business of Apps