The fact that you can talk to Siri to find directions is great as it is, but if you prefer Google Maps, then you’ll be disappointed when it opens up Apple’s maps application. Luckily, there is now a way to launch directions with Google Maps, without needing to jailbreak your device or downloading an application.
If you were to tell Siri, “Navigate to the nearest Apple store,” Siri will launch Apple Maps and you will get the directions to get there. However, if you prefer Google maps, then just add “via transit” to the end of your command and it will use Google Maps. So, just to be clear, you would say ”Navigate to the nearest Apple store via transit.”
That was simple, wasn’t it? Of coarse there are other jailbreak tweaks out there to do the job without you saying “via transit” but this is the simplest way to navigate with Google maps via Siri.