Announced a few months ago, the new app programming interface cuts off support for TweetDeck, as well as a handful of third-party Twitter clients.
The newly revamped Web site offers up a cleaner design and moves virtually all of the commands a user needs to a left sidebar.
Personal browser apps will go dead after May so TweetDeck team can focus on Web-based versions instead.
The refresh includes a revamped interface that boasts a new sidebar on the left for easier navigation across columns.
The Windows version now matches the look and layout of TweetDeck's Web-based app.
In March, Twitter announced it would focus efforts on TweetDeck's Web version. Facebook support, as well as versions for iPhone and Android, have disappeared.
The social network is tweaking its service after a rash of harassing and gruesome images and in an effort to bring more relevant information to people.
Twitter is laying to rest several versions of the power-user-friendly tool.
The application for power-users will cease to exist in three weeks, though the web app will continue as it is.
The update, meant to bring the Web and Chrome apps in line with features already available on TweetDeck's AIR app, will let users set a variety of column search criteria.