The following 3 pictures are humble suggestions to the Twitterrific application, the well-known Mac Twitter client. They depict the ‘active’, ‘inactive’ states, and the third is a concept for a potential Search feature.

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A summary of the changes:

• White, centered title instead of the yellow one
• Less cluttered bottom part: a single button, more writing real estate
• Retweeting feature and icon. Maybe the button of the user webpage should go too, so that only Reply and Retweet stay, which are message actions.
• Search feature. Upon pressing Command + F, the message input goes away and is replaced by search.