Hacker News Front Page Explorer - A database of top ranking Hacker News front page posts
Readwise - Effortlessly rediscover and organize your Kindle highlights
Hacker Newsletter - Best of Hacker News in your inbox every Friday.
Klib - Kindle & iBooks Highlights Manager
Hacker News-cli - Browse Hacker News from your Terminal
Clippings.io - Organize the notes you make on your Kindle