Adamant Messenger - The most secure and anonymous messenger, encrypted with Blockchain
Ripcord - A desktop chat client for Discord and Slack
Sonar - 2-way chat with your customers over SMS and FB Messenger
Slack - A messaging app for teams who see through the Earth!
ttirik - Unsure about giving out your phone number, but still need to make a call?ttirik is a free service that allows you to make calls with just a URL link.
Ziggs - Smoothly Share Content Between Devices!