Are you referring to the video framerate while viewing it on your iPhone? Or viewing it in icamsource on the computer? If you are referring to the framerate in icamsource, you could attempt to use a program called ManyCam, which serves as a camera cloner...making it possible to use the camera with more than one program at a time. I know that isn't really your goal...but ManyCam itself might access the camera differently than icamsource itself does...hopefully resulting in better performance. Before you try that, though, make sure you have the most recent webcam drivers installed for that camera. If you have to resort to trying ManyCam, make sure you get the old version of it. I mention the exact version number in one of my previous posts, which you can look through if you decide to try it.
Or, hopefully the SKJM guys have a better solution for you than my possible workaround.