StealthChat is an industrial strength chat and phone call app for professionals that value real privacy and security. StealthChat uses advanced end to end encryption to ensure that only the sender and recipient have access to the content of the message or phone call.
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Pithos - pithos is a daemon which provides an S3-compatible frontend for storing files in a Cassandra cluster.
Element.io - Secure messaging app with strong end-to-end encryption, advanced group chat privacy settings, secure video calls for teams, encrypted communication using Matrix open network. Riot.im is now Element.
Keybase Chat - End-to-end encrypted chat built into Keybase
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Pandora - Pandora Radio is a free (ad-supported) internet radio founded in 2000.