You may be amazed by knowing that Apple iPhone 4S is not the first device to get Siri. Siri was already there on older iPhones, but it wasn’t that good looking as the new one. Apple purchased the app and pulled it from Apple App Store just before the iPhone 4S launch so that users don’t get confused with the app.
The name was same, work and features were same; But It was developed by a third party developer. The App was not very much popular and had limited number of users. Modern Siri is much better than the older one, well that’s obvious. If you compare it graphically, You can note differences. Older Siri could do everything what modern siri does but not that efficiently.
Apple didn’t disclose any information about the “Siri” removal publicly but the developer Greg Kumparak said:
For one, it’s pretty tough to up-sell current iPhone 4 owners to the iPhone 4S if one of the biggest features is already available (albeit to a limited extent) as a third-party app. Less nefariously, having a third-party app (especially one that hadn’t been updated in around a year) available with the same name as a feature would be beyond confusing.
So Why did Apple named their own app as “Siri”? They could have had some other name for it. Maybe because Apple thought that the name can cause confusion between users.