Control sites using your hand (Youtube, Google Slides). Demo: https://hand-js.com.
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.