Samsung unveiled its much-awaited foldable smartphone in a bid to shake up a smartphone business awash with black, shiny rectangles that look increasingly similar. The basics, however, are clear. The device looks like a standard smartphone when closed. It opens like a book to reveal another 7.3-inch display, which would be one of the largest phone screens ever released. It will be big enough to run three apps side by side, up from two on the Galaxy Note 9, Samsung’s most-recent large smartphone. The company said the display can be folded hundreds of thousands of times.