
However it turns out that this isn't the unified messaging feature after all
This was confirmed by Francois Beaufort, the developer who first published the screenshot showing the new app icon. It turns out that he app in question is an internal application that the Chrome OS team built to test the new notification center. The app is called Notifications Galore and is even available for download right now.
You can find the instructions on how to install the notification app on your device and try it out for yourself.
Its about time Google released a unified messaging app for their platforms. Microsoft is offering a similar service on the Windows platform and Apple offers it with iMessage, so we hope that a unified messaging app from Google will arrive soon.
source - +François Beaufort