Grant Paul, known as chpwn (pronounced "cee-aitch pone"), lives in San Francisco. He was somewhat involved in the development of Spirit, Star and greenpois0n, and worked with westbaer on Star's website, JailbreakMe.

He also has developed tweaks available in Cydia, such as ProSwitcher (with Ryan Petrich), Infinidock, Infiniboard, Infinifolders, Gridlock. He has also done some work on Cydia itself (update to version 1.1.1).