Xiaomi Mijia LCD HandWriting Blackboard

This is either the most amazing piece of Technolgy or the most useless. It comes in two sizes, 10 inch and 13.5 inch screen (measured diagonally) and a stylus magnetically attaches to the side so it doesn't get lost (though it's easy to knock off).

The board is powered by a CR2032 coin battery which should last a year if the screen is erased 100 times per day.

It's a touch sensitive LCD screen, that's sort of like an e-ink screen, though it's black to start with and when you touch it, the screen goes white, though really green. It's a bit odd. The harder you press, the thicker the line (within limits), but it can produce some really good results and some drawings look really lifelike.

Since it only uses power to clear the screen, drawings will stay there until they're erased.

There's a switch on the side which when in the on position allows the button below the screen to erase what's on screen. There's no way to save anything, what's on the screen is it and touching the screen will just add more stuff. The only way to transfer images off the screen is to take a photograph of it. If the side switch is moved to off, then the button below the screen has no effect.

The stylus isn't anything special, it's literally just a pen shaped piece of plastic with a magnet inside and a pointy end. Anything can be used in its place (just beware of scratching the screen).

The case of the actual unit is reasonably thick ABS.

The 10 inch version is about £10 and the 13.5 inch around £18 from your friendly Chinese import site. Not a huge amount to spend on what's really a blackboard, but it's surprising good for drawing things and they seem to be popping up in TV quiz shows where contestants need to write/draw things as the contrast is pretty good and they're readable from a distance.

Amazing tech? The jury's out on this one, but cheap enough to have a play and not worry about it.