Steven Troughton-Smith, developer has effectively moved the voice-recognition system, Siri onto the iPhone 4. iPhone 4S Siri was performing well in iPhone 4, as the predecessor offered the required support.

To port Siri, developer was working with 9to5Mac. Both vocal and typed commands can be carried out by the iPhone 4 version of Siri. The voice recognition system can talk back to users as well.

A unique GPU driver is required for iPhone 4 however it is not integrated in iPhone 4S binary cache where Siri files are available. iPhone 4 version of Siri does not face any major hitches and works without any complications.

The original A4 processor does the job for iPhone 4 as it is powerful to handle the tasks well.