Cool stuff here. My comment is not on the app itself, it's on how it's being marketed. My initial impression was that this was some Google-affiliated 10% project or something based on the branding on the page, then I noticed the owner in previous comments say different.

The person who made this, if even for purely altruistic purposes, should be leveraging the eyeballs into some lifetime value, whether it's Twitter followers, awareness of who created it, clickthroughs to a blog, etc. It saddens me - as a marketer - to see a cool project like this essentially exist in the wild without an author's signature.