This could be a really great tool for analyzing soil color in the field, especially for wetland delineators (for comparison, the Munsell soil color chip book is currently retailing for $185+ on Amazon). I say "could be" because it's not QUITE accurate enough, at least for the colors I tested this afternoon. I used the app to measure the low-chroma color chips on the 10 YR page in the Munsell book (basically the wetland soil colors for my region). Preliminary assessment -- it did a reasonable job on the chromas (just looking at chromas 1 & 2; it's generally correct plus or minus a digit), it pretty consistently underestimated the values by 1 - 2 digits, and with the exception of 10YR 8/1, it generally got within a couple of hue digits. I imagine different devices would have different results, but if there was a way to calibrate the app for each device to improve accuracy (e.g., using a standard color calibration chart), you might just have soil science gold on your hands!
Wish it had color temperature
Fairly simple app, but gives the color value in a plethora of different color spaces. I wish, however, that it would let me adjust colors in those other spaces directly, and not require the camera to input them to begin with. By the way, what algorithm was used to convert to the Munsell color space?
Very useful for soil colour rather than having to use chart