What are some alternatives?
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.
Slack - A messaging app for teams who see through the Earth!
MagicPad - Free, simple, and private, offline text encryption suite.
Skype - Stay in touch with your family and friends for free on Skype. Download Skype today to chat and call on desktop and mobile.
Wire - Private & Secure Messenger
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.