This feature was available only for Android users.
But now, a developer has hacked the Daydream VR controller to make it compatible with iPhones.
Also, it is only compatible with Googles Pixel and Motorolas Moto Z smartphones running on Android 7.0 Nougat.
for the foreseeable future, iOS isnt part of Googles Daydream plans.
So, how did Pisani make the Daydream work on an iOS gadget?
He decided to hack the Daydream and make it compatible with iOS.
Next, he began the reverse engineering process and figuring out how to actually extract and use that data.
source: www.techworm.net