EpocCam HD on iOS supports automatic background removal functionality on devices with a TrueDepth camera. Those devices include:

iPhone X
iPhone XS
iPhone XS Max
iPhone 11
iPhone 11 Pro
iPhone 11 Pro Max
iPad Pro

All pixels that are further away from the camera than your face will be set to green color. This allows marking them as transparent when using PC applications like OBS or ECamm Live on macOS. Transparency is useful when overlaying your face on top of other video streams.

To use Green Screen / Chroma Key functionality, click the Chroma Key button on the EpocCam HD iOS app.

EpocCam will now track your face, and pixels further from the camera are colored green. You can change the color from green to blue or magenta from the app settings. You can also change the  cutoff distance.

For best results, ensure there is enough light in the room, but avoid direct sunlight as it will distract the infrared TrueDepth camera.

Chroma Key only supports 640 x 480 video resolution for now, as that is maximum resolution for the TrueDepth camera.