This is a recreation of Clear’s UI in HTML5. The demo was done by Evan You.
John Gruber over at Daring Fireball caught wind of this first, and posted a link. It seems that he’s tested it out on a few systems, and says that it only works properly on iOS. He tried it on Android, but said it’s very flickery. Chrome for Android worked for him, but not 100 percent, and it’s only in phones with Android 4 (Ice Cream Sandwich). With Windows Phone, which runs IE, it doesn’t work at all.
You can check it out here - http://clear.youyuxi.com/.