TubeNet

You've probably already addressed this but it's worth asking: does it need a special driver from the manufacturer, like a webcam would need?

Yeah, the J3 doesn't work with any of mine. Tablets don't usually work with them either. I have read that this could he because they do not provide enough power to accessories through the connection port to allow them to operate. You might be able to get a connector that will allow your endoscope to connect to a computer as one of mine has that ability, but that is no where near as convenient as hooking it up to a phone.