Ostrich will let you tweet, retweet, share links, get notified of new tweets, and more.
• Tweet This Page: Whenever you’re tweeting, there’s a button to link to the page you’re viewing. URLs are shrunk with bit.ly for minimal length.
• Unread Tweets: Ostrich keeps track of the tweets you haven’t yet seen. Mentions are also tracked so that you never miss a conversation
• Reply, Retweet & ★: The basic actions on a tweet are all available to Ostrich users.
• Mentions & Favorites: In addition to being notified of new tweets and mentions, they are conveniently added in their respective tabs.
More info and download link here.