You read it correctly, the Google Assistant gets a place on Apple’s iPhone to take on Siri. It was announced at Google I/O that Apple will roll out an app exclusively designed for iOS to cater the needs of the users with certain limitations.
— Google (@Google) May 17, 2017
This is a major break through and could well be the beginning of a new era and we may see more cross platform apps for these 2 different technologies in the future.
Right now, this feature is only rolled out for USA.
Via: The Verge