Back in July, Twitter started testing the ability for people to pin their favorite lists in its iOS app. It was a way to let users easily switch their timeline to view tweets from accounts they've added to a list, similar to what you can do on other Twitter apps like TweetDeck. At the time, that feature was limited to a select group of people, but now Twitter is rolling it out to everyone with an iOS device. This is going to allow you to pin (and unpin) up to five lists you follow or subscribe to, whose tweets you can keep up with directly from your main Home timeline. That's going to come in handy in case, you know, you want a more curated experience than what the top tweets or chronological timelines can offer.