Ohhhhhh, it may not be new, but I assure you - it is mind-blowingly awesome.
The problem it solves is app fatigue. I get this isn't a problem I have, but let me run you through the list of messaging apps I use.
- Slack - WhatsApp - HipChat - Facebook Messenger - Intercom - Kik - Social Media DM's - Skype (for messaging) - Google Hangouts (for messaging) - WeChat - Multiple Emails - I'm probably forgetting some because there are so many
It may not solve a problem for everyone, but if nothing else - it will be a lifesaver for me! :)