The tour map is scaled to the online map so you can use it with the offline map, and it offers more detailed information than the map comes with the device. The offline map when magnified will give you the street name around you, The Subway diagram is for finding different routes. No matter the complicity of the roads in Paris, the tool will make your life much easier find your way around.

The points of attractions can be searched by key word of category then plotted with loaded information such as visit duration, ranking, etc.

Restaurants can be searched by key word or cuisine type then plotted and highlighted

You can do a lot more with the app: Find your friends locations on the map, such as recording your locations then sharing your trips as named trails with friends, fitness, note keeping, timer, etc.

The larger app file size is due to the embedded offline tiles that you don't have to download yourself.