From the Apple website:
This update contains improvements and bug fixes, including:
- LTE support for more carriers (complete list of supported carriers at www.apple.com/iphone/LTE/)
- Purchase movie tickets through Fandango with Siri (USA only)
- iTunes Match subscribers can now download individual songs from iCloud
- New button to reset the Advertising Identifier
I also noticed that the update redesigned the music player bar for the lock screen and fixed an issue I’ve been experiencing with the iTunes store crashing when opened.