I looked on the website and there's no information on this. I'm sorry if I'm skeptical, but to me this looks like just another gadget for selling diamonds.
There are tons of other gadgets in the market. Sarin, etc. How can anyone be sure that any of them are "right"? For that matter, how do you know the 4C's on a GIA cert are "right"? What are the units for clarity and color anyway???
You have every right to be skeptical, but remember that we're talking about a diamond here. Even with all the technology available today, the "experts" at GIA still argue about the characteristics of the "ideal cut".
Bottom line, it's just not an exact science... if I were choosing a diamond today, I would use the isee2 gadget, in combination with a GIA/AGS cert, in combination with my eyeballs, and in combination with the opinion of a jeweler I trust.
HC