The Chromecast is a pretty cool device for folks who want to enjoy Google or other video content on their HDTV. It does not run the Amazon Instant Video app though. The folks behind Primecast have been working hard to bring that to Chromecast devices. Since the app was never official, it is not a surprise to see that it has been disabled already.
After only 36 hours, the app stopped working, and it has been pulled from the Google Play Store. It is not clear when it will be back. You can find the developer’s response on Primecast’s website.[Source]