I remember that a couple years ago Motorola was pushing its Moto Mods - hardware extensions you could clip at the back on your phone. I always thought that a Mod for alternate input (like this, or chorded/braille) would be very neat. Unfortunately looks like it never picked up.
Of course, but you generally need to hold the phone with the screen facing down (as you are supposedly hard of seeing, e.g. https://youtu.be/wueLXCbm_KY?t=45). Here you could have a touchscreen or tactile buttons seamlessly integrated on the back of the device.
Owning a moto Z phone, I was looking forward for this. Unfortunately, they never came with a real product.
I love typing on a hardware keyboard, I once owned an HTC Desire Z phone, which had a hardware keyboard and it was pretty great. Too bad nothing viable with a keyboard appeared since that time.
