The upcoming foldable iPhone that Apple plans to debut this September will operate like a cross between an iPhone and an iPad, reports Bloomberg. When the device is opened up, the UI will have an iPad-like layout that supports multitasking with two apps side-by-side. No iPhone to date has supported running multiple apps on the display at the same time, beyond simple picture-in-picture mode features. Many apps will feature sidebars on the left of the display, and developers will be given tools to adapt their existing apps for the new interface. The ‌iPad‌ interface makes sense because the iPhone Fold is something of an iPhone and ‌iPad‌ hybrid. When closed, it will resemble a traditional slab-style iPhone, but when open, it will be closer to the size of the iPad mini. Rather than a tall design, Apple is using a wider design than its competitors, and it is expected to have a 4:3 aspect ratio. A wider display will make the iPhone Fold more useful for side-by-side apps, video watching, and similar tasks that people …