Light Meter - Lux & Kelvin APP
It features direct reading in lux or fc (foot candles) and can display the measured light color temperature in degrees Kelvin (K) if your device supports this.
NOTE: This app requires device with a light sensor to function. Also, light color and infrared measurement works only on small number of devices. In order for this meter to be exact you need to perform a calibration procedure described in the apps's info screen.