It's OK - but... Rated 3 out of 5 stars
...has a tendency to "discover" multiple re-posts of an image in tumblr.com and hardly ever finds the original image.
I really want to find the owner of an image (in order to seek permission to use) - not just a stream of instances where the owner is not acknowledged.
The site of whoever first put an image on the web must be out there in the Google database somewhere!