U.S. bookseller Barnes & Noble has announced two new editions of the company's Nook tablets as entries in the ever-escalating tablet wars. The company said its 7-inch Nook HD and 9-inch Nook HD+ both feature a new user interface in a thinner and more lightweight design. Nook users will have access to more than 3 million books, a selection of magazines and apps as well as media content through the company's recently launched Nook Video and Nook Catalog portals, eweek.com reported Wednesday. The tablets will also feature a built-in email app that can connect to a number of personal and work-related email services, it said. The 7-inch Nook HD, at 11.1 ounces and 5-inches wide, will sell for $199, while the larger 9-inch Nook HD+ tips the scaled at 18.2 ounces with prices starting at $269 for a 16 gigabyte version. "We designed our larger format tablet Nook HD+ because we think there's big demand from customers for a super-light, extremely high quality 9-inch tablet, at half the price of the iPad," William J. Lynch, chief executive officer of Barnes & Noble, said in a statement.