If you’re accustomed to the vertical flip opening of phones like the Motorola Razr, or still fondly remember snapping your vintage not-so-smart cellphone open and shut, think different. The recently announced folding iPhone Duo opens horizontally, like a book, and its size and fold direction may remind you of a paper passport. The hotly anticipated phone was revealed at Apple’s latest event . While it wasn’t confirmed until Sept. 9, the folding phone was the worst-kept secret in tech, with hundreds of articles reporting that it was on the way. And it joins a crowded field of foldable phones, with key players including Samsung, Google and Motorola, as well as Chinese brands like Honor, Oppo and Huawei
