I am a bit confused.
I have been offline for some time, but where originates the Dutch list from? I currently see Amsterdam, Den Haag, Eindhoven, Enschede, Groningen, Rotterdam, Utrecht. Those are simply some of the biggest cities in the Netherlands. Are those entries added by other users because they live there? And which stations are in those city collections?
The official list with cities with radio towers in the Netherlands is Almelo,Almere,Alphen aan den Rijn,Ameland,Amersfoort,Amsterdam,Apeldoorn,Arnhem,Assen,Breda,Delft,Den Bosch,Den Haag,Den Helder,Deventer,Doetinchem,Dordrecht,Drachten,Ede,Eindhoven,Emmen,Enkhuizen,Enschede,Goes,Gouda,Groningen,Haarlem,Heerenveen,Heerlen,Hengelo,Hilversum,Leeuwarden,Leiden,Lelystad,Maastricht,Middelburg,Nijmegen,Purmerend,Roermond,Rotterdam,Sneek,Terneuzen,Terschelling,Texel,The Hague,Tilburg,Utrecht,Venlo,Winschoten,Zwolle.
Some offer a lot of radio stations. Others only the country wide stations and other only a few or even a single local radio station.
And there are a few cities with local stations transmitting with "micro" power output.
This is not efficient. It would mean that I need 775 png files where only 279 (the unique radiostations) would be necessary for all FM stations with RDS in the Netherlands.
If you only look at the country wide stations, I would need 111 png files for all cities instead of the 28 png files for the unique radio stations.
If this gets escalated over all the countries, it will be huge.
Unless you use a local internal sqlite database, where you collect unique png files in one table with a 1_to_many relation linking the unique png files to the many cities and frequencies. And this png files do not need to be in the database itseld. Only a pointer to the png in the assets (or res/drawable-anydpi or res/drawable-nodpi or res/raw. Whatever you like).
EDIT: It would also mean a drop-down list of 49 cities, if you count unique cities. This is not user-friendly.