Back in 2011, Ubuntu decided that it was time for the System Tray to be retired in favor of Application Indicators; and with good reason. The system tray was old, it was ugly, it had become a disgusting mash of icons that all responded to different input methods in different ways. It was confusing to use and it didn’t represent the direction that Ubuntu was taking. No one can argue that Application Indicators aren’t a huge improvement; and many Linux distros have followed suite, retiring the system tray in favor of an improved alternative.
Unfortunately, a number of applications didn’t update to make use of this new API; and whilst this wasn’t a problem at first (Ubuntu allowed you to white list apps), we’re now 5 years down the line – the system tray is gone, and any program that still relies on it won’t be able to sit in the tray.
Thankfully, there are some solutions!