Well, I solved my own problem. I ran these terminal commands to uninstall.
sudo launchctl unload /Library/LaunchDaemons/com.sweetpproductions.WiFiSpoofHelperTool.plist
sudo rm /Library/LaunchDaemons/com.sweetpproductions.WiFiSpoofHelperTool.plist
sudo rm /Library/PrivilegedHelperTools/com.sweetpproductions.WiFiSpoofHelperTool sudo security -q authorizationdb remove "com.sweetpproductions.WiFiSpoof.changeAddress"
Then I installed a fresh copy, ran the install helper and it worked.