Custom Wordpress plugin - maps with GPX tracks

I want to build a custom Wordpress plugin to show routes on maps in posts. The maps must be based on the Norwegian free maps delivered by "Kartverket" ([login to view URL]). I want the user to be able to switch between the different views. The key features must be: - User uploads GPX/KML file in front end posting when creating post/page - Button on/under map to download GPX/KML file - Responsive and mobile friendly - Easy switching between maps and layers - Always displays map on all posts in specified categories (alternatively on pages/posts with GPX data) - Interactive altitude graph under map (as in example) - All labels must be transelateble - Button to open route in google maps - Custom fields to display distance, lowest/highest point, climb/descent based on GPX/KML info - Option to show one map with all routes and places in page using shortcode or similar Here you can see on example of "Kartverkets" data in use with Leaflet [login to view URL] I want it to look similar to above link, but with more layers options. Here is Kartverkets online maps: [login to view URL]!?project=seeiendom&layers=1002,1015&zoom=12&lat=6670416.66&lon=258136.60 I am not sure of how much time this takes and therefore the price, but i want a fixed price in any case.