This extension is a page action, that acts on the website. As the user clicks on an item link, the item ID is parsed and stored in the HTML5 storage database (
localStorage). Automatically this item will be moved to the bottom of the website (marked as read).
This was a frustrating extension to build because of the fact that the HTML source in the Hacker News website is a total mess. Parsing it turned out to be an unreliable task, not only because the site layout is done with tables, but also because of the lack of semantics in the markup.
Anyway, it seems to be working fine (with some minor bugs being taken care off). I’m currently using it and it’s making a big difference making me focus only on the news that I didn’t clicked yet.