Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
Pithos - pithos is a daemon which provides an S3-compatible frontend for storing files in a Cassandra cluster.
tawk.to - tawk.to is a free live chat app that lets you monitor and chat with visitors on your website or from a free customizable page
Pandora - Pandora Radio is a free (ad-supported) internet radio founded in 2000.
LiveChat - LiveChat - premium live chat software. Approach customers directly on the website, make connections and drive more sales using LiveChat.
Keybase Chat - End-to-end encrypted chat built into Keybase