First, find out which version of Cardboard you are using: does the Cardboard have a button on the upper right or a magnetic ring on the side?
If your Cardboard has a magnetic ring on the side, you have a Cardboard v1.0 and Kubity does not support this model as Google no longer has a Software Development Kit for v1.0.
Kubity supports Google Cardboard v2.0. This version of the Google Cardboard has a universal input button in the upper right that works with all phones.
Learn more about Google Cardboard and where to find one here.