The App in iTunes is for your phone. Are you running the iCamSource program on your computer? If not, you can get the Mac or Windows version here:
http://skjm.com/icam/support.phpYou need to run iCamSource on a computer with a webcam in order to view the webcam on your iPhone. Once iCamSource is running on your computer, select your webcam from the Video drop down list and your microphone from the Audio drop down list (or No Audio).
Then set your login and password. You can set the login and password in iCamSource to be anything you want. Make sure it’s something other people won’t be able to guess easily.
In iCam on your iPhone, make sure you are using the exact same login/password you entered in iCamSource on your computer. To edit the login and password in iCam on your iPhone, click the "i" button in the bottom right corner of the screen. That button will take you to the Settings page, where you can edit the login and password.
There is more information about setting up iCam here:
http://skjm.com/icam/help/