Hi,
Djaydino is right, you'll need to build the feature from scratch, because on touch screens, there is no such things as a mouse, so there is now cursor to follow around.
I would however split the camera rig, your camera ( rotating around the horyzon axis) should be parented to an empty gameobject ( rotating around the up axis), itself parented to another empty gameobject. That way you have proper control over each rotation, and they won't get mixed up.
Bye,
Jean