Feedmark by jasonbirchall

Feedmark turns one bookmarks folder into your RSS subscription list.

Create a folder called "Feedmark" in your bookmarks, drop in the sites you
want to follow, and the toolbar button starts counting unread posts. Open the
popup to see the latest items per site; click a site to read it, which clears
its count. If a site doesn't advertise its feed, paste the feed URL once and
you're subscribed.

There's deliberately little to it:

• No account, no server, no sync. Your subscriptions are your bookmarks;
  everything else stays in local browser storage.
• Feeds are fetched directly from the sites you bookmarked, over https only,
  every 15 minutes.
• Nothing is collected, tracked, or sent to anyone. See the privacy policy in the code repo.

Manage subscriptions the way you already manage bookmarks: add, rename, move or delete a bookmark in the folder and Feedmark follows along.