I'm not asking to implement this, but I would love to know why not choose OpenStreetMap over Google Maps? There are tiles that look similar to google's (https://github.com/mapbox/osm-bright) and it's completely open. No idea what's the state of OSM in your country, but it would be neat to see an app this polished. Yet, I know that people want Google Maps because they already use google, so I'm only wish to know your opinion on the matter.