I was thinking about getting a Apple TV thingy. My wife has a iPad air and I would like to know will the Apple TV play what ever is on her screen. I know you can stream Hulu, Netflix, etc. but can it play what is showing on her iPad at any time like her web browser? Is the Apple TV just Apple's version of a Roku box? Didn't want to spend $100 on something that will wind up just sitting there.