The tube is at the heart of London travel and when something goes wrong it can quickly affect a huge number of people. Using London Tube Status for iPhone you can keep up to date with the latest tube news so you will always know if there are problems on a particular line.
Icons are used to indicate the status of individual lines so you can tell at a glance whether your planned route is going to be problem free or not. If a problem on the line is indicated, you can click through to find out more information.
The app is updated with all of the latest information and this is saved ready for offline access. This means that when you are travelling on the underground it is still possible to read the status of lines from the last update.
The idea and execution of the app is simple, but it does not suffer for this - it does not need to be a complicated or overly fancy program to deliver useful information.