Apple has unveiled its first folding iPhone, the Duo, with a starting price of $2,000. The phone features a book-style format and is one of the most expensive smartphones on the market, with the highest storage option priced at $3,200. CEO John Ternus described the folding features as "fluid and completely intuitive," but critics warn that the phone may become a "premium-priced ornament" without significant growth for the company. The foldable iPhone, a work-in-progress for several years, aims to redefine the experience of using a foldable phone and differentiate itself from other models on the market.