If you find incorrect information being returned by the API, or if a city, state or country is missing, please open a support ticket with the information and I'll gladly update the API database.
Do you need some extra information to be returned? What about some extra endpoints?
I'll be adding the ability to control if the query is searched only for cities, states, countries, all of them or any combination. For example, if you only want to search states and cities that match your query, but exclude searching the countries list.
Another feature in progress is to include country codes and phone codes, also with the ability to select which data you want instead of returning all columns.
In any case, if you need some other feature to be added just open a ticket and we'll talk about it.