iPhone 4S' most talked about feature is without doubt, the voice command assistant, Siri; despite Apple's recommendations, hackers have tried to port the Siri Assistant on other devices, especially older iPhone models.
Now, according to JailbreakNation (opens in new tab) it seems that Apple is itself testing Siri on other devices, in particular, they say, the iPhone 4. The technology website, quoting sources "close to Apple", says that Apple has released among its employees software versions that allow them to use Siri on other devices. At the same time, security measures around the prototypes have been tight, as they don't want employees to be seen using the devices in public.
Following the results of these internal tests, Apple will decide if it might be a good idea to expand the voice Assistant feature to other devices. Currently, the voice activated technology is exclusive to Apple's newest smartphone and relies not only on software but also on compatible hardware, such as the dual-core A5 chipset and the high-fidelity microphone on the 4S.
Technology enthusiasts have tried to port Siri on other devices with some noticing that the hardware spoils the Siri experience. However, one hacker who got Siri to work on an iPhone 4 reported '100% functionality' with his demo video showing just a marginal delay in comparison to the 4S.
If Apple does find that Siri is capable of running well on the iPhone 4 they may consider introducing it at some stage, though they will be wary of losing a unique selling point of the 4S too early on.