Hi, friend.
I did this application some months ago and I think that's exactly what you need.
In the CS module you will find a GetUserLocation Client Action wich contains a javascript to get location ready to use.
In interface module you will find a block with a map that shows the location passed by parameter.
I did not that to show any ads. You can use another option like Leaflet if you find any issue with google maps.
Let me know if it helps.
Kind regards.