Gnome Shell Extensions
Firefox Add-On
This extension provides integration with GNOME Shell and the corresponding extensions repository at the https://extensions.gnome.org website.
$> sudo apt install chrome-gnome-shell
After that, you can visit the Gnome Extensions website and install any extension directly, with a click on the page,
App Indicators
To support app status notifiers in the Shell:
Many still will not show up, for some also install the following:
Lock Keys
Numlock & Capslock status on the panel.
Printers
Manage Jobs and Printers.
GSConnect
GSConnect is a complete implementation of “KDE Connect” especially for GNOME Shell with Nautilus, Chrome and Firefox integration. It does not rely on the KDE Connect desktop application and will not work with it installed.
“KDE Connect” allows devices to securely share content like notifications or files and other features like SMS messaging and remote control. The “KDE Connect” team has applications for Linux, BSD, Android, Sailfish and Windows.
KDE Connect Indicator can support Gtk desktops other than GNOME Shell.