From Ebner Verlag GmbH & Co KG:
K-White enables you to use your IOS Device as a white balance target.Using simple swipe gestures, you can change the color of your white balance target to achieve a warmer or colder look or for example compensate for the green tint of flourecent lights.Looks can be saved and recalled allowing look management even for longer film projects.Instructions:* Set your target color by swiping across the display. Keep in mind that a cooler target results in a warmer image.* Hold your IOS Device in front of your camera and press the white balance button.*Check the resulting image on a monitor or camera display.*Once you are satisfied with the result, save the target.