Impressive! Working as a Gaffer I use it time to time to check the temp on the lamps if any of them looks suspicious. The app really impreses with the accuracy: +/- 200K but that's totally acceptable. Worth every penny if you don't have colormeter on you. Need to have a trained eye though, to recognize a misreading.
Can tell the Difference I just bought this and took photos using my Sony A35 with Minolta 50mm f2.8 prime lens comparing it to the Auto function and various other settings. Used f stop of 4 for all comparison photo's and then shutter speed to match f stop. Tried it out first just analyzing the subject. The color temperature was definitely off when compared to Auto. Second series I followed the instructions by taking a picture of white paper placed in front of the object first to analyze. The difference is between night and day. The photos I took using the Color temp settings looked like I had used fill flash. The colors were more true than using the Auto feature. It also brought out more detail than the auto function. I would post comparison photos but this does not let me. I would recommend this App, but if you plan to rely on it I would make sure you always carry a white piece of paper with you.
Works with a gray card I use this with the X-Rite Color Checker Passport's gray card and it works well enough to set the white balance for my BMPCC that doesn't have a built-in white balance function. Probably depends on the the phone you're using and the accuracy of the phone's camera. I'm using this on a Nexus 6.
You have to know how to use it When using this app, you must take a reading from where the camera is positioned. For instance, if the camera is in a doorway and shooting towards windows, place a white card (or gray card) in front of the lens of the camera and take the reading. One of the biggest problems with ANY colorimeter, are the bulbs being used today. Take average readings of all light in the room, You will get anywhere from about 3000 - 42000 and you must average that out to midway but must also guess at which are the strongest lights. Nothing is perfect these days when shooting indoors but I find this one gets me close and easier to process. Much more reliable than relying on most camera AWB feature. They've NEVER worked for me.
Surprisingly accurate on my devices I tested this application against several known color temperature sources and it reported the color temperature/Kelvin within a very small variance to the expected number. Nexus 5 running stock Android 6.0.0 rooted it was consistently within +/-100K. Nexus 7 (2013) stock Android 6.0.0 rooted it was less accurate varying by +/-200K. Samsung S5 Android 5.1 consistent within +/-200K. Surprise results on Amazon Fire Phone FireOS 4.6.3 rooted varying +/-100K.
very useful I used it to measure color temp and set my 5D3, and comparing pict with the one taken with full auoto mode. I didnt tell my wife which one is auto shot and she picked the manual one as the better colors. nice.
MONEY BACK GUARANTEE - If you are not happy with the performance of the app on your device, let me know and I give you a full refund! Valid within a whole month from the date of purchase.