In the Android app, we've recently implemented a "nearby" feature that plots nearby articles on an actual map, with tiles retrieved from https://maps.wikipedia.org
So far, this feature is only useful at relatively narrow zoom levels (i.e. level 15+). If we zoom out any farther than that, then the number of nearby articles (especially for an area dense with relevant content) becomes too much for the user to wade through:
It would be useful if the API allowed us to specify a "zoom level" parameter to filter search results based on zoom scale. For instance, if I zoom out to fit the entire state of Ohio into my viewport, I would expect to see Wikipedia articles corresponding to major cities or counties in the state, and not any particular districts or establishments within any city. As I zoom in to a particular city, I would expect to start seeing city-specific articles, such as landmarks, museums, etc.
Of course, this would also necessitate expanding the "radius" of the nearby search to much greater than the current 10km :)