tarkin is getting technical support through email.
For informational purposes, the answer to the question is:
The iCamSource program does need to be running on your computer in order for iCam on your iPhone to connect to it, even for Wi-Fi cameras. This is due to the firewall/NAT piercing techniques used by iCam. Also, the motion detection features of iCam (push notifications and motion recording) require iCamSource to be running in order to perform the motion detection processing.