Show the top bar (panel) on demand while having full screen content on (like a YouTube video). Just hover the mouse cursor to the top of the screen, and the panel will show up. This way, you can quickly check the time, or swich some toggles. This is similar to what macOS offers for full screen apps. This extension is incompatible with Blur My Shell extension.

Extension Homepage

https://github.com/marcinjahn/gnome-peek-top-bar-on-fullscreen-extension

Download

Shell version… Extension version…