On the Note 3 and presumably the Note 4, if you do this weird flick gesture on the screen, one handed mode is engaged. It's okay, but not perfect as it reverts back to full screen mode if you inadvertently mimmick the gesture on the screen. From memory the outline of the one handed mode screen is the entire Note 3 footprint albeit shrunk, and it includes all the hard buttons such as the volume rockers. Now what about if Apple went one better, and instead of having the whole screen drop down with 2 taps of the home button, instead have the screen size shrink down to 4 inches, ie the same size as the 5S? So picture the 5.5 inch screen, and within that screen, you have a screen the same size as the 5S, superimposed, sitting bottom and centre, and which is operational. The remainder of the screen outside of the 4 inch rectangle would be blanked out and not responsive to any multitouch gestures. Surely this would be more practical than reachability. It would effectively allow you to work a 4 inch screen when you need to or when it suits you or when you just plain feel like it. Granted the larger width and the bezels of the 6 plus will still make it more difficult to hold and use with one hand than a 5S but surely it would be way more useful than than reachability. The problem with reachability is, it gets a bit draining having to tap twice everytime you want to reach something at the top. At least with what I am suggesting, you double tap once and everything is shrunk and stays shrunk, until that is you double tap again. Points to note: 1) Double tap home button for 4 inch mode when required. 2) 4 inch mode remains in 4 inch mode until you double tap home button to go back to full screen. 3) Whilst in 4 inch mode, your thumb reaches all corners of the 4 inch space as it sits at the bottom of the 5.5 inch screen. 4) Still able to rotate in landscape. 5) Everything you can do in full screen mode can be done in 4 inch mode, including notification and control centres, texting and app-ing, however everything will naturally be smaller, ala the 5S dimensions. 6) Double tap home button to revert back to full screen mode and away you go. 7) Unlike reachability, you will not have to double tap every time you want to reach something at the top of the screen as the 4 inch screen will be locked in until you unlock it. 8) For those who prefer reachability, you could still have it but maybe make that 1 tap of the home button. I hope Apple is considering something like this. For those who do not want too see this, remember, you do not have to use it. Simply don't double tap. Disclaimer: I have not scanned every single thread of this site so if this has already been suggested or discussed, apologies.