Very Handy App
We used this a lot in Paris last week. Very helpful in easily selecting the quickest route to your destination, as opposed to studying the maze on the Metro map. I simply picked two nearby Metro stations as start points and had the app map out the route to my desired end station. I then picked the shorter route of the two. The app displays a line graph for you showing each of the stations you pass through with a note showing the correct direction to board in each transfer station. Hint: you may want to pick the route that avoids the bigger transfer stations (e.g., Gare du Nord, Concorde) because you will have a long walk in those stations to the connecting Metro line.
Mike3M about
Guide Metro Paris