Keyboard overlay in mobile device layouts

I apologize if this has been requested (nothing came up when I searched) or if it’s a function that I’ve missed …

When designing for mobile apps, it would be super handy to have a grey box that one can turn on to see where the keyboard is going to hit and design around it. I know there are workarounds (the one I’m currently using has been to create a grey box the size of the keyboard and simply add it to every phone layout) but a more elegant solution would be appreciated.

Interesting idea, definitely useful for prototyping too. thanks for the request!