The updated version of Seesmic for iPhone adds a few new features to the mix. The biggest change is support for Retina Display in iOS 4. It brings tweets into sharper focus on iPhone 4 and the new iPod touches. Seesmic also finally supports multitasking, which lets the app run in the background and quick-launch from the multitasking menu.
The app also makes some UI improvements. Loading new tweets used to require clicking the refresh button, but now Seesmic for iPhone supports the very popular "pull-down to refresh" interface that Twitter for iPhone (formerly Tweetie) popularized. A new threaded conversation view for @replies and direct messages has also been included in the updated app. The app adds Twitter List support as well, specifically the ability to add friends to lists.
The list of updates to Seesmic for iPhone goes beyond Twitter and bug fixes, too.
Facebook improvements include an updated News feed UI, messages support and the ability to see a list of friends and friends' profiles. Finally, Seesmic for iPhone now includes integration with Instapaper and ReaditLater, allowing you to select articles to read later in Seesmic.