Haha. We’re developing a water quality app, leveraging the camera, for volunteers, interested public, etc. Idea is to use an image of a Secchi disk, lowered part-way into the water. RGB gives us 3 values, which should allow us to map back to absorbance at the wavelengths commonly used for WQ (perhaps using some remote-sensing-like techniques, or maybe we’ll just do something like some black-box curve fitting). My background is CS, but I have some side projects, mainly with limnologists. But I’ve never taken an actual Secchi reading in my life. 
Won’t be as good as a real lab, of course, for a variety of reasons, but it’s something.
I can PM/email more if you are interested, though I can’t seem to figure out how to PM on pixls.us.