I tried to find a review/video of anyone actually 'playing' the thing. Only tried four but not a single one gives an example of how well it works. This makes me think that it has zero musical qualities and is nothing more than a tactile device.
This could be useful, but I also found something really interesting. It is a lot more expensive but there is a midi device called a jam stick that has a similar form factor as this, only slightly larger. It can connect to your phone, tablet, or even computer for home use and actually works as controller for a midi guitar instrument on the device (tablet/phone/etc.). If you search "jamstick review yourguitarsage" you can watch a pretty comprehensive video about it. It can also be used for any midi input in a sequencer/DAW (as inpu for any midi instrument, such as violins or piano, etc.).
One Ring to rule them all, One Ring to find them, One Ring to bring them all, and in the darkness bind them.