The Live Viewer for Action Cameras app allows you to view the live stream of your GoPro Hero, DJI Osmo Action, Xiaomi Yi 4k+, and SJCam camera via WiFi. The tool is also compatible with the webcam driver which allows you to use your camera as a webcam in your favorite apps (Zoom, Skype Desktop, OBS Studio, ...).
IMPORTANT: Please take a look at the website for a full list of compatible cameras and their restrictions: http://www.tequnique.com/action-webcam#cameras
Demo video: https://youtu.be/r5HhGQzc9Ag