In multi tests Siri shows a lot disadvantage from Google's Google’s new Google Search application, which includes a version of Google Now, that can be used to search the Web through the Google Search app even on these older iOS devices that don't have Siri.
One problem with this application is that you have to launch the application to use the voice assistant feature. A new free jailbreak tweak dubbed NowNow by iOS developer Nick Frey allows you to set an Activator action in order to launch the Google Search application and load up the Google Now voice assistant. This will make it behave more like Siri on iPhone 4S and newer devices that support Siri.
When you install NowNow, just head over to the Settings application and you’ll be able to choose your Activator action. If you want to simulate Siri, we recommend using the hold home button Activator action, since this is how you launch Siri on a Siri-enabled device. You can, however, use any Activator action that you wish to.
If you have the Google Search application suspended in the iOS device’s memory, then you will get an almost instant response from the Activator action. If you don’t have the Google Search application open already, you will see the application open when you invoke the Activator action and then the voice assistant will load up. This is something to keep in mind if you want it to be nice and quick. You may be able to work around this by never closing out of the Google Search application from the app switcher when you close out of other apps. Even if you are waiting for the app to load, it really doesn't take too long.
Available for FREE on Cydia via BigGoss, NowNow is a nice little workaround for non-Siri devices. And if you want to have a faster voice serch, try NowNow!