Maybe it could just be a JSON file with the xpath of all important elements?
Also maybe it doesn't really have to be a service. It could just be a file on github, where anyone could issue a pull request if gets broken broken. That way way you would essentially crowd source it.
Also maybe it doesn't really have to be a service. It could just be a file on github, where anyone could issue a pull request if gets broken broken. That way way you would essentially crowd source it.