Orsome has launched another great app, however this time targeted toward Christchurch users (for those fortunate to live here)
http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftware?id=286729253&mt=8
Shows route information and uses GPS to find the closest bus stop, where it shows real-time arrival information from Metro.
Currently Free on the App Store
http://www.orsome.co.nz/MetroInfo.html