The National Rail app (Train Travel), which is perfect for any commuter in UK, has been updated to 1.5. The changelog lists live tile support and Twitter integration as the two alterations in this version, coupled with improved help and tutorials.
The live tile can display any journey you've planned by saving any given timetable. The depart time (and date) is then displayed as well as the station codes. I did a test run with Shoeburyness (SRY) to London Fenchurch Street (FST) and the tile updated within moments as well as displaying the time we expect to arrive at the destination.
The app can be downloaded for a hefty £4.99, but is surely worth it if (like me) you use the trains a lot. Head on over to the Marketplace to purchase Train Travel (opens Zune).