I created a simple add-on to see which posts / entries are new in the HN first page that is the posts that wasn't there when last visited. This is different than /newest page.<p>note: I am new so sorry if title is wrong.
Note about add-on:
When you first intall this, all the posts in the front page will be colored to red, this is normal because all the posts are new since there is no existing data about previous visit. You can refresh the page so that everything will back to normal.<p>You will see the benefit when you, say one hour later, enter the HN again by seeing only the new posts in the front page will be colored to red.