If you want to run Icamsource and view on Icam, a computer needs to be on.
If you want to view a USB webcam on Icam, it must be connected to a running computer running Icamsource.
If you want to view an IP camera, you will need to set up the cam with the computer, but it will not need to be left on as the camera will be connected to the router, wired or wireless. The camera can be viewed on your smart phone using one of several apps. If you want to view the IP camera with Icam, the computer must be on running Icamsource.