The isn't a proper mod in the traditional sense - it's an extra program you run that makes a map and adds it to your Minecraft saves, so when you launch Minecraft, it's ready to play. If you've been on these forums a long time, you might remember my older generators that worked the same way. (My new one has all most of those as options too.)
Here's a screenshot of the sort of world this new one makes:
There's a custom nether too, but it's a bit tricky to get to
Though this isn't a mod in the same sense as most, I'm starting to think it fits best on this board. Calling it a "tool" make people think it will make pictures of their maps instead of making a new map in the game...
Let me know if you try it out. We're very open to feedback, and we'll be adding more generators as time goes on too. Our next major update will likely be adding support for the Win10 beta.