In case you haven't noticed, Twitter got a makeover.

CEO Dick Costolo revealed a new look for Twitter's profile pages on the web, mobile apps and the iPad on the TODAY Show.

The iPhone and Android Twitter apps are available for upgrade now.

The new profiles now feature header photos so users can express who they are more meaningfully on Twitter. Users can upload an image from their mobile device and see the same profile design on their phone, tablet or computer.

Twitter will also be rolling out photo streams for the images people have shared on Twitter. Whenever a user sees a photo stream, they can swipe left or right through the thumbnails or tap to view photos in fullscreen mode. Android users can also get closer to photos with pinch-to-zoom.

Twitter has also given iPad users an opportunity to expand their experience, claiming that they have rebuilt the Twitter for iPad app "from the ground up to make it fast, beautiful and easy to use."

In the new Twitter for iPad, users can expand tweets with a single touch to see photos, videos and web page summaries in their timeline. With another tap, users can see the photo, play the video or read links from the web in fullscreen mode.

With the upgrade, users can keep conversations going by tracking their interactions with other people: See who has followed or mentioned them, retweeted or favorited their Tweets.

Twitter for iPad give users the opportunity to discover information personalized for them. They can read news stories that are popular within their network, see which Tweets and accounts are favorited and followed by the people they know, see what topics are trending, and find great new accounts to follow.

Twitter now gives users the chance express themselves by adding a new header photo to their new profile, similar to Facebook's cover photo. It appears consistently above the Tweets on iPad, mobile apps and twitter.com, and can be changed anytime.

Twitter announced that there are over 140 million users, with 340 million tweets per day. Twitter also values $8 billion and has 900 employees based in San Francisco.