Until someone does you can use the following HNSearch queries: [1], [2] and [3] (roughly best to wrost). Note that you'll get HN apps along with HN clones.

[1] https://www.hnsearch.com/search#request/submissions&q=%22hac...

[2] https://www.hnsearch.com/search#request/submissions&q=show+%...

[3] https://www.hnsearch.com/search#request/submissions&q=%22sho...

Edit: [2] finds this 'Show HN: Hacker News for "Hacker News for 'X'"': https://news.ycombinator.com/item?id=5436841.

Edit 2: Improved the search queries.