Slow Feeds is a feed reader that lets you filter your feeds by posting frequency.
Most blogs and many, many websites support feeds and push their newest articles, news and posts out into the world in an easy to use, open feed format (like RSS).
Slow Feeds lets you subscribe to any and any number of those feeds, lets you star your favorite articles, mark them as read or unread, or unsubscribe from feeds again.
If you have an account on Bazqux, Feedbin, Feed Wrangler, FeedHQ, Feedly, Inoreader or Newsblur you can access it with Slow Feeds. Or you can use it as a standalone app.