So I installed Viber on my Ubuntu 14.04 and had the realisation that the notification icon was at the wrong place (top left instead of with the other icons on the tray).
I followed the instructions at Annoying Viber notification and installed the viber indicator program. This was working fine for a while, but at some point (possibly after updates) viber indicator can no longer launch. I tried re-installing it but is still refuses to launch. I can still launch Viber normally but that doesn't help because the indicator is again at the wrong position.
Update:
For anyone who may run into this in the future, as of (possibly) version 6 of the Linux client for Viber, the notification is behaving correctly without the need of any other packages to be installed.