Live Present Slides од Randy Lubin

Make Google Slides appear in 'Present' mode while still being editable. Just hit fullscreen and you're good to go.
This item automatically hides or removes elements from Google Slides presentations so that only the slide is visible.

This is meant for cases when you want a slide to take up the whole screen but you want to be able to live edit it from another tab or computer. This is particularly great for games or workshops where you are updating data during the event.

Just make your browser fullscreen and hit the extension's icon. If the page is still loading, you may need to hit it a second time.

Inspired by Raph D'Amico's brilliant hack.