NowNow is a new tweak from Nick Frey that makes it easy to replace Siri with Google Voice Search.
Start Google Voice Search from anywhere in iOS, much like Siri. On install, setup an Activator method in Settings.
NowNow is especially useful for older devices and firmwares that don't support Siri. It's recommended to use the Short Hold home button method for the best effect.
NowNow requires the latest Google Search app installed from the App Store. You can download the tweak from the BigBoss Cydia Repository for free.