It is the only map application that allow you to check public transport (bus/metro/tram) with changes other than (if it exists) a local app for the city.
As far as I know, there is no other map application that does that.
Exactly. Here in Tokyo, there is a local app that's tied into public transit just like GMaps, but all it does is tell you how to get from Station X to Station Y. If that's all you want to know, it works quite well. But most people want to know more than that: where is Business A, and what's the fastest/cheapest way to get there from my current location? Which station exit should I use? And oh yeah, how are the reviews on it? And can I see the menu, and place a reservation too?
As far as I know, there is no other map application that does that.