After only three days of exposure, Amazon has had Primecast blocked from use. From what I understand it was restricted via Amazon’s backend. That means there was no legal action taken against the Primecast developers or threats of action. The developers have taken the app down of their own volition.
Contrary to what was written on Gizmodo and other blogs, the developers are working to refund everyone who bought the app. If you have yet to receive a refund, contact the developer directly. Their information can be found on the Primecast website. I have reached out to the developers for comment and will update or post again with anything relevant.