Let's say I develop audio player for iPod Touch 4/iPhone. Currently it can be controlled with standard panel (double click Home and scroll left). But how can I control that with built-in voice control (long click on Home)?
Apple has a VoiceServices framework (more info here) that may do what you want. Unfortunately, the VoiceServices framework is not part of the public SDK and it can't be used in apps submitted to the store.