VR app development, unity camera face downward when i face my xperia c4 camera downward during selection

This is what i have observe since my phone do not have gyroscope. In my created app, buttons exist. this buttons will transfer 2D scene to a VR scene. When I face my phone camera downward then click the buttons choice.. The scene transfer into a VR scene with a face downward camera scene. when I face my camera phone upward then click the buttons choice.....The scene transfer and now the camera scene in vr is upward. When I face my phone to left, the vr scene change to right and right change to left. M problem is that is there any other way manipulate this things in order for me to create a VR application with out using Gyroscope sensor..eed answer ASAP..