On my first trip to Tokyo, I took a variety of tools with me in order to find my way around the city's train system. Maps, complex apps,and then a little piece of software called this app. I had never expected that not only would MetrO be as useful as it ended up being, but that I would only need it and nothing else.
With a lot of other apps, they're about trying to shove complex maps or information onto a small screen. With this app, I get only what I actually need: clear and easy-to-understand directions on how to get from the station I'm at, to the station I want to be at. And, of course, because this app works offline, it's always there for me at times that other apps have no ability to be.
I've now used this app for both visits to Tokyo and San Francisco, and it's never let me down. Such an amazingly helpful and convenient must-have tool when traveling. I appreciate that MetrO is free, but I'd easily pay money for it if it weren't.