Contractors spend a lot of time (=money) just trying to measure service before quoting. That's the market.
Reading the blurb, it seems like it's some sort of instant measuring tool.
However, the truth us hidden in the middle of the FAQ: You have to include a special proprietary "target" in your photo and the iphotomeasure will use the size of that target in your photo to calculate size of nearby objects.
No rocket science - just simple scaling.
(I'm getting tired of this i-mania)