Google Maps API - get my own map

I searched Google API for a way to load my map (google.com/mymaps). When I download a map, I mean POI. I didn't find anything other than google mapsengine api, but there are two problems:

• the map id of my map is not valid for the mapengine api - https://developers.google.com/maps-engine/documentation/reference/v1/maps/getPublished returns 404
• Creating maps in maps is not as easy as it is in my maps.

The problem is that my client wants the android app to display the map he created earlier. And he wants to create it using Google Maps.

Question: is there any API that allows me to load this data? Or, if not, what is the way to get this card? The only idea that comes to my mind is to load the KML map file, but I would rather use the REST api if possible.