FaceNiff is an Android app that allows you to sniff and intercept web session profiles over the WiFi that your mobile is connected to. It is possible to hijack sessions only when WiFi is not using EAP, but it should work over any private networks (Open/WEP/WPA-PSK/WPA2-PSK).
It’s kind of like Firesheep for android, but maybe a bit easier to use (and it works on WPA2!).
Do note that a rooted phone is required. Please note that if the webuser uses SSL this application won’t work This application due to its nature is very phone-dependent so please let the author know if it doesn’t work for you.
There’s a great video demo of it working here:
You can download FaceNiff here:
Or read more here.