We've been looking into using the Google Chromecast with a custom receiver to allow a user to use an app on iOS, Mac, or PC (node-webkit is used for Mac and PC) and then show different content on the TV with the Chromecast to what is being displayed on their device. So that we can do stuff like reports, status boards, etc.
We'd like to also support the Apple TV... but I've not seen anything on the Apple Developer site regarding displaying HTML content other than just video and audio or mirroring the entire screen of the iPad or iPhone. We'd want dual content.
I have seen screenshots on the Apple website showing games that have different content on the the device to what is displayed on the screen.
Can anyone offer advice? As it looks like it's possible... but the resources and information on this are difficult to find.