It might be in extras or testing, can't check right now sorry.

It's an amazing tool, I've used it for so much. It lets you build your own packets *exactly* how you like them. So for this you'd need to build a malicious ARP packet and sniff the connections. I can't tell you how good it is until you use it. You just need to know some python (mostly for scripting your stuff, if you're using the interpreter it isn't a lot like python) and a good knowledge about networking.