I’ve been using this for blocking out levels in Blender: https://gumroad.com/l/gOEV
Feel free to PM me on the forums, Gitter or through Wire if you want to improve your Blender workflow.
What do you mean improve my workflow?
I gave it a try and it seems like a nice utility. I think the most useful thing is probably the snapping features.
My biggest complaint is the painful download process. Why do I have to register an email and everything to get it? Just put it on github and save everyone the hassle.
So you can easily donate to the author.
Instead of making Blender easier to use through add-ons I could maybe help you (or anyone else) improve your workflow using built-in functions, some of which you may currently be unaware.