Just got back from Tokyo. I have to say the app is very good. If you get lost and find a train station. Enter in the name and your destination and bam. It tells you which line to take and where to connect. The only confusing part was, I wish it had more information like which track number to take or the last station that line is stopping at. We got lost and spent almost 1 hours going one direction, only to find out we were going the wrong direction and wasting more time back tracking.
So maybe in the a future update. Track numbers to take or maybe a minimap of the direction the train will travel so we dont go the wrong direction and having to back track.
RB3381 about trains.jp, v0.1.1