How to find out WiFi password on Android phone?

Question

Android

Hello.
Once I connected from the phone to the neighbors' WiFi network (I got the password for a chocolate bar). Connected 2 phones on Android (on one 2.3, on the other 4.0 version). Now he brought a laptop to work, but lost the password sheet somewhere. How can I see WiFi passwords on my phone?
PS Neighbors do not mind connecting, it's late and it's inconvenient to ask for a password now)

Answer 1

In the file /data/misc/wifi/wpa_supplicant.conf

Answer 2

WiFi Key Recovery. Need root.