I would be happy even without the "cheap". I would really love it though if they made an open (in the sense of iOS/Android at least) operating system for such

I would be happy even without the "cheap". I would really love it though if they made an open (in the sense of iOS/Android at least) operating system for such phones (yes, monochrome and with CPUs in single digit MHz probably) It would allow for third-party applications (or, at a pinch, I could write one myself) that no phone or watch manufacturer ever makes right. Like UI customization for texts or alarm clock that makes sense for polyphasic sleep. But this, I'm afraid is a thing that will never be made: all innovation seems to be in the segment of touch-screen slate phones nowadays.