If you have an iPhone, EpocCam is the app I’d recommend for turning it into a webcam. However, the free version includes intrusive ads and very few features, almost necessitating the $7.99 paid ...
While a laptop typically comes with a built-in webcam, desktops do not, and laptop cameras can break at any time. You could purchase a new webcam, but if you don't want to shell out for more home ...