It won't just be Samsung with a foldable phone out on the market, and while the South Korean giant might be first, a foldable smartphone will only be real once Apple does it. Right?
Apple has filed a new application for a US patent on a foldable electric device with a flexible display, but the application does state that the device could be a "may be a laptop computer, a tablet computer, a cellular telephone, a wristwatch, or other electronic device". I don't see foldable laptop screens or a tablet being worthy just yet, but a foldable iPhone makes sense.
Remember that Apple hasn't received the patent, and it could be years and years before anything comes from it.