Having spent almost 20 years in Philadelphia iSepta is one application that I can relate to.
SEPTA, for the uninitiated, is the South Eastern Pennsylvania Transportation Authority. SEPTA runs Philly's popular Regional Rail line which is a series of trains that connects downtown Philadelphia with its suburbs.
Back in the day, SEPTA.com only had PDF schedules on their Web site which was horrible because it was easy to end up with dozens of PDF schedules scattered all over your hard drive. They've since made HTML schedules available but they're super-wide and anything but mobile friendly.
Enter iSepta, which lets you plan your trip from your iPhone. Simply click the 'New Trip' button, enter your starting station, then select your destination station. You'll get a list of the next five trains scheduled and an option to view the full weekday and weekend schedules. You can even swap the From and To stations with a simple button to see the next trains available for your return trip.
Every city should have something like this. Do you have something similar where you live? If so, pimp it in the TalkBack below.