Design Toolbox is a collection of tools designed to accelerate and simplify basic modeling tasks of architectural, urban or interior scenes tools: Standard transformations by reference, like the ones usually found in more precise work oriented applications; Fast measurements, speed up positioning of reference coordinates and workplanes. It also includes some other useful tools for quickly apply and manipulate uvw maps, for paneling simple surfaces; plus some others useful time saver tools.
DesignToolBox is packed with our previous tool, refGuides:
refGuides includes a set of tools intended to improve and facilitate accurate modeling, particularly helpful for modeling architectural scenes. This tools allows to create construction lines guides, for accurately position and model objects. They can also be used as rulers, displaying measurement units in the viewport. Other great added feature is the ability to snap to intersection points.
Look at the changelog about the new tools added.