Hacker News Stack - Focus on the really fresh and unread news in Hacker News.
HackerWeb - A simple and readable Hacker News app
Hacker Newsletter - Best of Hacker News in your inbox every Friday.
HackerScroll - Read top articles from HackerNews in a clean, simple and minimal interface without ads or any other distractions.
Hakaran - Hacker News Rankings for story/show/ask, update once daily
HNwatcher - Track keywords and users on Hacker News