A startup is building a smartphone-connected gadget that aims to tell you if the pill you’re about to take is really what you think it is by shining light on it. A scan of a known Viagra pill with Stratio’s LinkSquare spectrometer shows that it matches a reference scan. San Jose-based Stratio’s device, called LinkSquare, is a tiny spectrometer, a device that measures the intensity of wavelengths of light.