Current iPad #1 apps on iTunes store, Tweetbot for the iPad is everything you love about the iPhone app and more! EVen better than current native twitter client, IMHO.
Tweetbot — A Twitter Client with Personality for iPad
Tweetbot is a full-featured iPad Twitter client with a lot of personality. Whether it’s the meticulously-crafted interface, sounds & animation, or features like multiple timelines & smart gestures, there’s a lot to love about Tweetbot.
◆ Multiple Timelines. Quickly switch between your lists as your main timeline.
◆ Smart Gestures. Use Twitter more efficiently with time-saving and configurable gestures.
◆ Native Push Notifications.
◆ Customizable Navigation. Hide the navigation tabs that you never use.
◆ Support for multiple services like Read it Later, Instapaper, Cloudapp URL Shortening.
◆ Save drafts, add locations and POI's, attach photos/videos, manage your lists, and much more.