Apple’s iPhone Duo could finally make foldable phones mainstream

Apple’s iPhone Duo
With the iPhone Duo, Apple has entered the foldable smartphone market years after Samsung, Google, Huawei, and others, and it is doing so with a $1,999 book-style device designed less as a novelty and more as a bid to change what mainstream buyers expect from a phone.
The iPhone Duo, unveiled September 9th, folds from a compact 5.4-inch outer display into a 7.6-inch inner screen — Apple’s largest iPhone display yet — while keeping the same aspect ratio