Using this extension you can play/stop videos on YouTube or advance onto a next slide by simply raising your hand. Simply go to a YouTube page or start a presentation via GoogleSlides. A minimized popup icon will be shown on a page - and you are ready to go. A hand must face the camera directly and be upward. Please take a look at the https://hand-js.com for a quick tutorial. Although the extension requires access to your camera, the data is used only locally, it is not transmitted in any way.