The 280 Norths (the same people who made iReddit) are making one. I suggested they charge $5 because they won't sell as many. Arguably it's worth it, because having fewer users is part of what makes HN good.

Any place where we can find dev details on that?

I couldn't find any mention of it at: http://280north.com/

Does HN have an API, or would it have to be scraped?