You can download the update directly on your device through the Apple App Store or by using the following link:
The Netflix for iOS update has the following new features and improvements:
- Netflix HD for iOS 7
- AirPlay streaming for iOS 7 (requires disabling AirPlay mirroring)
- Playback optimizations
- Stability improvements
Back in 2011, Netflix said that they would never support AirPlay and suggested that users use the dedicated Apple TV app instead. However it looks like the company has changed their stance with their latest release.