Called WiFiPhisher, if I understand it correctly, it jams your existing WiFi, pretends to be it on a different channel, then captures your password as you re-authenticate on “its” channel. Clever hack. Comes with Kali so I maybe trying this out soon.
http://www.theregister.co.uk/2015/01/05/snooker_wpa_secrets_with_this_wifi_tool/
https://github.com/sophron/wifiphisher