EpocCam is a free application that helps you to convert your mobile camera into your PC’s Webcam.
On its free version, it doesn’t support HD Video recording. You can use it with your smartphone both Android and iOS. While you can use both Android and iOS through Wi-Fi but USB support is only available for iOS.
First, Connect your smartphone with your PC using Wi-Fi or using USB Cable. Then start the EpocCam app on both your PC and Mobile. Then follow the instruction and start using your Mobile camera as Webcam.