If they're a clamshell style with a physical keyboard, as with the Psion Series 5, possibly: <https://en.wikipedia.org/wiki/Psion_Series_5 https://en.wikipedia

If they're a clamshell style with a physical keyboard, as with the Psion Series 5, possibly: <https://en.wikipedia.org/wiki/Psion_Series_5 https://en.wikipedia.org/wiki/Psion_Series_5> Folding-screen phones are an expensive gimmick, with inevitable exceedingly expensive repairs: <https://arstechnica.com/gadgets/2023/09/the-pixel-folds-screen-repair-will-cost-900/ https://arstechnica.com/gadgets/2023/09/the-pixel-folds-scre...> I predict a flop along the lines of 3DTV.