Yes there are! We are making them faster than we can write about them. I've made a couple in the last few days:
Offsetter: Simple functionality for offsetting paths.
Inlay Generator: Technically you could do this manually with the offsetter app, but this rolls the math into a simple app that creates both the female and male parts required to make an inlay. Here is some more details on the app.
Dogbone Generator: This one has been in my mind for a long time. Basically, if you have a design that has parts that need to fit together, you need to manually add "dogbones" in order to fully cut out inside corners. I posted an image, explanation and use case on this post.
And that is just my stuff, I know the other devs have also created some (like the awesome Voronoi pattern generator). We are all trying to write apps to get a feel for where the process can be improved. We are also coming to understand what we need to provide developers in terms of libraries and data to make it as easy as possible.