NITROX3D is not an addon, but rather a workflow that works with Blender's existing modifiers. The NITROX3D workflow (Non-destructive Iterative Techniques for Rapid Object eXploration in 3D.) enables you to quickly model in a parametric-like workflow, much like the expensive CAD systems, but without all the overhead and cost. While NITROX3D cannot model everything (a car, a character), it does work well for a surprisingly number of products and ArchViz models.