Integrate Street map and Metro Map
Allow the user to Pinpoint either a Station on the Metro Map (already done) or a point on the Street (Perhaps a point of interest). If the user flips from Street Map to Metro Map it will lodge the Pin in the nearest Metro Station to the point of interest. Vice versa if the user Pins a Metro Station and then flips from Metro map to Street Map; the App takes him to the Street Map with the pin Located at the Metro Station is on the Street map. If there are other points of Interest in the Vicinity these should be showing on the map as well.
I realise that this requires a proper integration with Street Maps and information of what is in the street. Therefore I am upgrading my download of the App to help you achieve this. When you do you will have a truly powerful App that you can develop for every city in the world. And if you need someone to help with content and Sales in Europe and USA. I'm your man. So don't loose my email address.