I personally really don't see the need for one of these and find it lands and takes off with ease. Once the spark has landed on the palm of my hand and the motors have shut down I simply just give it a little gentle squeeze with my fingers to make sure I have a good grip on it and that it simply wont just fall off and get damaged.
I've seen a few of these on aliexpress. Not a bad idea for people who may be nervous of the spinning blades of doom.
Of note, I think this is a better idea than the clip-on finger guards seen in other threads. Those add weight and create a blockage to the prop thrust, which would reduce flight times. This serves the same purpose, and obviously has no effect on the flight.
I'm not sure why people are afraid of palm landings. You're not supposed to try and grab it, simply hold your fingers out straight and allow it to land on your flat palm. Once the blades stop, then you can grab it. Are people trying to grab it mid-air?