not_constantinople creates place-names from a blend of cultures, e.g. "three parts English, two parts Catalan, one part Assyrian". In other words, you can create names that don't sound like generic high fantasy using it.
I created not_constantinople as part of a much larger worldbuilding project; I wanted to populate a map with town names but I was struggling to imagine them on my own (especially if I was less familiar with the cultures in question). When I later found out that sci-fi writers were interested in it, I cleaned it up and released it for free.
The challenge in creating it was finding a big enough corpus of place names sorted by culture. I eventually converted Crusader Kings II's data files into a (heavily modified) json file.
not_constantinople has a few more planned features, in particular: a web app version, and a personal name generator ("not_constantine").
Download not_constantinople here.