What exactly are you looking for? A random world generator, or a tool that makes drawing maps easier? I’d just draw it myself, with some actual maps for reference. If you’re bent on making it realistic it does take some time, but I think it’s worth it. At least it’ll be your world that way. In fact, I’ve done this before. Twice. It’s much more fun to do it yourself. :) I based my maps on a layman’s understanding of plate tectonics. I created one big “pangaea” continent first and then made sections of it drift apart. I love plagiarising the real world. :P