I'm looking for a webapp that each day it track some field inside of a html page ( it could be a product price). And then you can make a graph with the evolution of that price. I'm sure that I read something similar here in HN, but I can't find it.
I'm working on one right now. Will be a few months before its ready. There are some that are specific to stores, etc... that shows pricing trends but not sure on a universal one.
