Very useful status menu for locating and unmounting removable drives.
https://extensions.gnome.org/extension/7/removable-drive-menu/.
Very useful when using removable drives a lot.
A very useful addon for Gnome shell. This adds a very useful application menu.
https://extensions.gnome.org/extension/3628/arcmenu/.
A very useful extension to disable the screensaver when you are doing something important and do not want interruptions.
https://extensions.gnome.org/extension/4135/espresso/.
This interesting extension will set your Gnome wallpaper to the current Bing website background. This would be a great way to have a random wallpaper every day.
https://extensions.gnome.org/extension/1262/bing-wallpaper-changer/.
MMOD Panel. This is a great top panel for your Gnome Shell Desktop. This looks and feels great. It also has customization under the Gnome Settings dialogue.
https://extensions.gnome.org/extension/898/mmod-panel/.
I tested this with Gnome 3.36 and it works fine.