Pocket (formally Read it Later) rebranded itself as a digital pocket. You can throw articles and videos you want to remember, tag, or read/watch later. This is a great tool to store articles or links you don't have time to read right away. In my workflow this is handy when saving links from Twitter or Google+, or other apps I use to discover (Flipboard, Feedly, Google Reader). Then, when I have time, I can go back to read them. Unfortunately, my pocket ends up being a wonderful storage place because I never have time to read everything! In recent updates Pocket enabled offline reading. I appreciate the tags, stars, and ability to archive (and search). I typically use Pocket's Mac app, iOS, and the Chrome widget for saving an article. Wonderful tool that aids in research and learning presented in a distraction-free environment.
On the iOS app there isn't an easy way to tag an article when you are in the view mode. You have to back out and then swipe to bring up the tag feature. Pocket works with over 300 apps for capturing content and is viewable online, iOS, Android, and OS X.