Reminds me of Firesheep. Simple side-jacking implemented as a Firefox extension with a real simple GUI. I recall that this prompted so many websites to migrate to HTTPS.
It wasn't just a GUI, it was even a browser extension.
I'm surprised there isn't a popular point-and-click Windows GUI for ARP spoofing yet. Something like driftnet but all sorts of data, and with automatic spoofing done.
I've used Cain & Abel before long, long ago. It's pretty close to what I'm talking about, but I was thinking more of something revamped to be pretty and user friendly even to someone who has no idea what ARP is or what "spoof" means.