This extension is 'appindicators' from ubuntu, renamed 'top indicator app' under the terms of the GPL v2 +. it is the extension itself that Ubuntu offers as a native experience on your system, but so you can install it in other distros since the current one in gnome-extensions is empty.I will offer stable updates when possible.

Extension Homepage

https://github.com/ubuntu/gnome-shell-extension-appindicator

Download

Shell version… Extension version…