If you're big into iOS, AirPlay is a great method for streaming audio and video content between your Apple devices. But it's not perfect. Your iPhone and iPad can only stream out, for example — not the other way around. And your AppleTV will only accept the file formats supported in iTunes. These aren't quite deal breakers, but they can be annoying restrictions.
Luckily, there are are a few third-party solutions with AirPlay support — and they enable your Apple devices to do all the things they normally can't. If you've ever wondered how to re-direct audio (and sometimes video) from nearly any application or player to your iOS device — including all that new Spotify goodness — here's how.