I'm assuming from context that your mean keyboard, but the idea sounds kind of cool so I have to ask: any chance this is a term for a a bluetooth device solely designed to facilitate copy-pasting between other devices?
For cross-device control, there's ... Synergy, I think:
There's an Android client (I've no experience with it): https://sourceforge.net/projects/synergyandroid/
On the Android, there's Termux which offers a clipboard interface -- termux-clipboard-get and termux-clipboard-set which I've aliased as "xp" and "xc" respectively. (I have similar aliases for Linux and MacOS's respective clipboard manipulators.)
You can paste (including to remote SSH sessions) with the ctrl-alt-v keystroke.
It's possibly to select and copy screen regions, but tediously, so that piping to / from xc / xp is far more convenient. (I sometimes use this for composing / editing HN comments, more frequently on other sites.)
In practice, I end up manually typing in long URLs on my laptop that people send me over SMS or whatever, and manually typing in long, high-entropy passwords on my phone when I would rather copy-paste them from my laptop's password database.
(Not that I'm running KDE. But the feature sounds great.)
edit: I should mention that I think this requires drivers on the computer end, so probably won't on iOS/Android
Nor, for that matter, can you click, ctrl-A (yes, Virginia, I have and use a Bluetooth keyboard). Instead it's click, then Copy Icon.
Utterly blinkered.
Oddly: Incognito mode is not (yet) crippled in this manner.
Don't get me started on pull-to-nuke-whatever-you'd-been-composing-or-losing-your-place-in-infernal-scroll