The YouTube iOS app was updated today to version 1.3, adding a variety of new and improved features.
According to the update notes listed in the App Store, version 1.3 brings these new features:
Quick access to new uploads for subscriptions via "My Subscriptions" feed on the Guide
Access to Live streams
Queue up videos to play on TV
One Channel branding for video creator channels
Stability and performance improvements
This is the first major update to the YouTube app since the end of February, when Send to TV and the ability to record and upload video via YouTube Capture were added.
