But MetroTwit is not all about looks: It is a serious Twitter client, with a heavy emphasis on configuration and flexibility. Just about anything is configurable, from which columns to show and how to title them, to which columns will pop up notifications, to where exactly those notifications should pop up (what corner of which screen, if you have multiple screens), and for how long. If you can think of a preference, it is probably something MetroTwit lets you change.

The emphasizes animation and responsiveness, and MetroTwit delivers on these principles, feeling fast and fluid. Progress bars are razor-thin, taking up just two or three pixels of vertical space. It's not perfect, and sometimes the interface gets a bit too clever. For example, the scrollbar has two indicators--one to show your current position, and one to show where the unread tweets begin. Due to the flat Metro look, none of these indicators looks like something you can "grip" to scroll, and I would routinely confuse the two and click the unread indicator instead of gripping the scrollbar handle. Once, I was unable to make the unread indicator go away, even after scrolling all the way to the top of the column: MetroTwit still insisted there was a tweet I didn't read, but I couldn't find it anywhere.

Twitter is a great medium for conversations, and MetroTwit has an easy conversation view feature that lets you see exactly what tweet the other person is replying to. If your conversation is more than two tweets long, MetroTwit shows the entire conversation, with the oldest message at the bottom.

MetroTwit's free version is powerful and flexible, but it will only let you connect to Twitter with a single account, and it shows a banner on top of one of your columns (true to form, it lets you pick which column). To use it with more than one Twitter account and make the banner go away, buy MetroTwit Plus ($15 Australian Dollars, about $16 as of April 2012). While the Plus version is very full featured, it still won't let you schedule tweets, which is something you can do with .

MetroTwit's innovative look and feel are a sign of things to come, but its solid functionality and flexibility make it a Twitter client you can use today.