Wow, were have you guys been, these dongles already exist, negating the need for the Apple TV. I personally use the
EZCast. It's a great little product, supports DLNA, Miracast, WiDi along with AirPlay. I'm always carrying along the EZCast when I'm traveling and even just out and about. Though I really rarely use it with my iPad Pro as I'm just not a real fan of how iOS streams it's desktop to external displays. The resolution and aspect ratio are hardly ever supported, DPI looks comically huge, doesn't support extending the desktop but the biggest thing for me is I can't connect my little mini Logitech Dinivo. So Instead I use my new Google Pixel C (which I just love) or Surface Pro 4. With the Pixel C I use a great little app called Second Display, with it, I can; extend the desktop and not just mirror it, both the resolution and aspect ratio of any external display I connect to is supported (including every app that is installed), I can also even change the DPI to reflect that of a normal desktop. Which means when I boot into either Remix OS or Arch Linux both of which are Installed and in a triple boot, I have a really nice desktop machine connected to a TV in the hotel room for when I'm traveling. I can also, unlike my iPad Pro, stream a movie to the TV while the kids use the Pixel C to play a game like Modern Combat 5 at the same time and with two game controllers.