In the latest release I've added a refresh button for the camera and mic dropdown boxes. If you have a chance, give it a shot and let me know if that fixes the issue.
It seems like the culprit is Nvidia Broadcast program creating tons of weird virtual cameras.
If you're having this problem, uninstalling Nvidia Broadcast seems to fix the issue and will display your webcams properly and allow tracking. No idea if there's a way to fix this and still allow Nvidia Broadcast to stay installed. If you find a way, let me know. Also, if this doesn't work for you, let me know. (facetracking.exe shouldnt be appearing in the cameras dropdown at all). Thanks!