Twitter refreshes iPhone app interface, adds new Tweet composer, notifications when friends sign up

Twitter has updated its application for the iPhone and iPod touch with a refreshed user-interface for the Tweets timeline.

Additionally, the updated application features a new Tweet composer interface that actually allows users to preview what a posted Tweet will look like in the timeline. Also notable is the new ability to receive notifications when friends join Twitter.

Improvements and fixes for the Lists functionality are also present in this 5.7 update. 

The new Tweet composer for iPhone makes sharing photos easy and lets you preview how your Tweets will look. Also:
• Enjoy a more beautiful design on iPhone with wider timelines in all parts of the app
• Receive a notification when a friend has joined Twitter
• Improvements and bug fixes for lists