All three platforms available for our application have a so-called system notification area, which is also known as the system tray. That's a part of the user interface (in the bottom-right corner on Windows and top-right corner on other platforms) where you can find the application icon even when it's not present on the desktop. Using the NW.js API (http://docs.nwjs.io/en/latest/References/Tray/), we can provide our application with an icon and drop-down menu in the tray, but we do not have any icon yet. So, I have created the icon.png image with the text Fe and saved it in the application root in the size of 32x32px. It is supported on Linux, Windows, and macOS. However, in Linux, we can go with a better resolution, so I have placed the 48x48px version next to it.
Our application in the tray will be represented by TrayService:
./js/View/Tray...
