Hacker News Reader

Android version. Notifications for followed subjects and followed users' comments. Offline mode. Links to the url in the Archive, Google cache, etc. Maybe a tag or icon if the url is a video, pdf, etc or favicon from the website. A sidebar with a list of all the urls posted in the comments for easy.

The possibility to configure interesting topics and having the client check in the background if anything relevant pops up.

If it's open source I could try to add the feature myself.

Bookmarking , theme