How to install Google Assistant and enable the "Hey Siri, Ok Google" shortcut to get access to Google's voice assistant on your iPhone.
This is what happens when you ask Siri to open up Google Assistant
How to Make Siri Run Google Assistant Commands on Your iPhone « iOS & iPhone :: Gadget Hacks
GOOGLE ASSISTANT IS NOW A STEP AHEAD OF SIRI
Google Assistant for iPhone Review
OK Google: How to Use Google Assistant on iPhone, Android
Google Assistant & Remote Vehicle Action (RVA)
Google Assistant now lets you send and request money from your contacts
iPhones can access Google Assistant by voice command - Reviewed
Google Assistant for iOS is now available in Europe - The Verge
Google assistant not availible on iphone? : r/GoogleAssistantDev
How to Make Siri Run Google Assistant Commands on Your iPhone « iOS & iPhone :: Gadget Hacks
How to Turn Off Google Assistant
The Google Assistant comes to iOS
Google Assistant on iPhone is Now Easier Than Ever to Activate