Twitter is killing off TweetDeck. TweetDeck announced that it'll be discontinuing the iPhone app, Android app, and Air-based multicolumn desktop app. The apps will be removed from all the app stores and stop working "shortly thereafter".
To continue to offer a great product that addresses your unique needs, we're going to focus our development efforts on our modern, web-based versions of TweetDeck. To that end, we are discontinuing support for our older apps: TweetDeck AIR, TweetDeck for Android and TweetDeck for iPhone. They will be removed from their respective app stores in early May and will stop functioning shortly thereafter. We'll also discontinue support for our Facebook integration.