This is a sniffer. The intent is to sniff HTTP packets and attempt to reconstruct interesting authentication data from websites that do not employ proper secure cookie auth.
As such this tool only sniffs traffic going outbound with a destination port of 80 (by default but can be overriden via optional parameter)
Does this work on SSL?:
Sure. If you can perform SSL MITM you can use this tool on the interface with the decrypted traffic. Since such tools already exist I will not recreate their functionality here. For MITM attacks I prefer
ettercap but to each his/her own. There are a few ways to attack SSL. SSL Strip does a good job of forcing unencrypted traffic if HTTP is available and ettercap can perform SSL MITM.