By using iPhone camera, you can measure a spectral intensity of the light by a spectrum image from a spectrometer.
Press camera > photo button to shoot a spectrum image dispersed by the spectrometer. If reflected light is observed, please be the in the area of the dark rectangle on the upper side of the camera screen.
Press the graph button to show the light intensity distribution of the spectrum calculated by the camera image.
Because it is very dangerous, please never see strong light such as the sun, and please do not put it in the iPhone’s camera.