This app was mentioned in 3 comments, with an average of 1.67 upvotes
VR Controller app for Android can turn your old smartphone into Minecraft VR controller! https://www.facebook.com/vrcontroller/ https://play.google.com/store/apps/details?id=com.vasosoft.android.vrcontroller
I found this one but never try it yet https://play.google.com/store/apps/details?id=com.vasosoft.android.vrcontroller