Edit: source https://transition.fcc.gov/eb/jammerenforcement/jamfaq.pdf
Edit 2: selling and marketing it is also against federal law, and the seller appears to be a US resident with credentials listed in the Kickstarter. Facepalm.
The video has a disclaimer to only use this on one's home network for protection. However, less than a second later it is shown in a car, presumably for wardriving.
The text of the page says in passing that multiple attacks can be launched, yet only one is described. If I need to deauth people on my network, I think I'll do it myself.
Great idea, though! Thank you for sharing.
This kickstarter should not exist.
It's a scam.