You could implement your own using the shapefiles from http://efele.net/maps/tz/world/ http://efele.net/maps/tz/world/. They have derived the shape files from f

You could implement your own using the shapefiles from http://efele.net/maps/tz/world/ http://efele.net/maps/tz/world/. They have derived the shape files from fip10s data which itself is derived from VMAP0 data. We created a rough implementation similar to this at postmates using this information but didn't find it worthy of open sourcing.