It’s not exactly an implementation of Webmention, but I was interested to find that there’s a tool from Hypothes.is that will show you (all?) the annotations (and replies) on your website.
https://jonudell.info/h/facet/ and then enter the appropriate domain name followed by
/* as a wildcard to search.
- Aaron Davis: https://jonudell.info/h/facet/?wildcard_uri=https%3A%2F%2Freadwriterespond.com%2F*&max=50
- Ian O’Byrne: https://jonudell.info/h/facet/?wildcard_uri=https%3A%2F%2Fwiobyrne.com%2F*&max=50
Now wouldn’t it be cool if this were available in the main UI? Perhaps if there were a button for “Site notes” or highlights? This may be unwieldy for the New York Times, but could be reasonable and very useful for smaller personal and/or academic based websites.