Use your phone as a real lux meter for free! Lux-o-Meter is the first Windows Phone 8.1 application for measuring real illuminance using the built-in light sensor, now also with the option to use alternative illuminance units: Foot-candle, Phot or Nox. It's now also possible to disable the automatic lock screen. The application is free, but if you like it, you can update it to Pro version, thanks! Because of missing light sensor the application does not work on: Nokia Lumia 530, 630, 635, 636