The job of the lens attachments is to change focal length of native lens and hence change field of view or minimize the focusing distance. While the lens parameters may be close for different smart phones, how universal a given attachment can be is often highly depends upon mechanical considerations. For a lens attachment to work property it needs to be mounted accurately relative to the native camera lens. This can be challenging with the wide variety of smart phone designs. When made correctly, the image quality of a lens attachments should be close to the image quality of native lens with minimum distortion and chromatic aberrations.