The "Routing App Coverage File" is a GeoJSON file which describes the coverage area for a public transit routing application (to be used with iOS 6 Maps). The iTunes Connect Developers Guide says:
Routing app coverage files are .geojson files which specify the geographic regions supported by your app. The file can have only one MultiPolygon element. MultiPolygon elements consist of at least one Polygon. Polygons contain at least four coordinate points. Polygon start and end coordinate points must be the same.
Of course if your app doesn't have anything to do with public transit routing, you can ignore this.
