The demise of Google Reader provided a clean slate, making it possible for other news readers to flourish. Feedly has positioned itself as a strong contender, but there are many others. Digg entered the battle with Reader.
Digg Reader was rather bare bones when it launched, but it's been getting better. Digg has now released a Chrome extension for Reader, making it possible to stay up to date without actually having to keep the website open in a tab.
The extension provides a quick way to see how many unread items you have. It also makes it easy to subscribe to the site you're currently visiting. Finally, the extension works as a shortcut to the Reader site.
It's nothing fancy, quite the opposite, but it doesn't have to be. It's a useful extension that complements the existing Digg Reader. Digg could have built a full-blown Chrome app, but it probably wouldn't have made it any more useful.