Signal is a messaging app for simple private communication with friends.
Signal uses your phone’s data connection (WiFi/3G/4G) to communicate securely, optionally supports plain SMS/MMS to function as a unified messenger, and can also encrypt the stored messages on your phone.
The executive chairman of the Signal Foundation is Brian Acton, a co-founder of WhatsApp. Signal is the lovechild of two pieces of software from Whisper Systems, which launched in 2010: RedPhone, an encrypted voice calling app, and TextSecure, an encrypted texting platform.
Is Signal app owned by Elon Musk? – No, but his tweet with a recommendation had a big impact on the growth of downloads of this messenger in January.