You know not all's well with mankind when devices like these seem like a good idea.

The Substitute Phone is a weighted plastic block that comes with rollable beads in the middle. You're encouraged to swipe your thumb across them, as you would to unlock your phone or scroll up and down the screen -- a gesture most of us do hundreds, if not thousands of times a day.

The beads are made of stone, and the entire device is made to feel and weigh similarly to the average smartphone.

The gadget comes from Austrian designer Klemens Schillinger, who's listed it on his website. While perhaps more a work of social commentary than a genuine retail product, the Substitute Phone doesn't seem that out of place in an era of fidget cubes and fidget spinners.

He's designed a range of them too, that mimic different common gestures we do all day.

Obviously, the device is entirely analogue and won't actually replace your phone. But if you've ever stood in a lift or in line for food, and mindlessly started swiping at your mobile, you're just the target for the Substitute Phone.