Apple will be streaming its iTunes Festival every night in September and the music performances will be available across multiple devices. In addition to the ability to use AirPlay Mirroring to stream to your TV through Apple TV from your PC, Apple has gone ahead and released a dedicated app for iPhone and iPad.
It has a breakdown of all the performances and news, and will have streams to watch live on your devices. If you miss them live, you can re-watch individual performances for a limited time, too.
Download iTunes Festival for iOS.