The easiest way is to have a web interface that you can access by the iPhone, other than the examples above. I know that the Denon
AVP-A1HDCI has such an interface, it's been referenced in the AVSfourm threads (or page 68 in the manual).
Though I would find it better to use this interface to save various setups so we can do backups of settings when doing firmware updates and other configurations.