Boop Light Detector
Boop is an an app to detect levels of light and interpret this information with sound. It allows its blind and visually impaired users to detect whether lights are on or off. It covers a broad range of light levels which spans from sensing daylight through open windows to checking whether the indicator light is on for a wifi router.
More information: https://itunes.apple.com/us/app/boop-light-detector/id1134857212?ls=1&mt=8