I’m a sucker for good UI design and Tweetie 2 for iPhone is no exception. The specific UI feature that impressed me the most is their list refresh mechanism. Exciting right?

As you might have guessed, Tweetie is a Twitter client, and the primary use for a Twitter client is viewing a list of tweets. This list of tweets changes over time so the UI should have a refresh button of some form. Back when Tweetie 1 was released, it was one of the first apps to integrate the refresh button into the list view as a hidden item at the top, a trend which has now taken off and can be seen in many other apps like Facebook for iPhone. To refresh the list of tweets, you would scroll to the the top of the current list, then keep on going to reveal a refresh button or link. This is pretty good since the most recent tweet is always at the top of the list and if you want to see even more recent tweets, it makes sense that you would try to scroll up even further.

But, this requires you to perform 2 actions. You have to scroll beyond the top of the list and then you have to press the refresh button. Tweetie 2 solves this in the best possible way. Scrolling beyond the top of a a list in Tweetie 2 reveals a handy little instruction and animated graphic that instructs you to scroll up further and then release your finger to refresh the list. This is the ultimate solution since performing it requires almost no thought or input from the user. The user can just scroll off the top of the list and it will automatically refresh and load more items.

In my view, this solution is so perfect and intuitive that I can easily see this becoming a design convention in pretty much all 3rd party apps with a refresh mechanism. In fact, I think it’s so good that I wouldn’t even be surprised if Apple starts adopting it in their own applications.