The tour map is scaled to the online map and offers more detailed information than the map comes with the device.

The points of attractions can be searched by key word or category then plotted on the maps.

In case get lost, you can plot your location latitude and longitude and send to people who are looking after you.

You can do a lot more with the app such as collecting then sharing your trip as a named trail with friends, displaying your friends location, etc.

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