BluePrintTools-Pro 2.1 for Mac can be downloaded from our website for free. The application lies within Design & Photo Tools, more precisely General.
From the developer:
BPT-Pro let you draw simple blueprints, design with dimension lines or even measure over a curved line. BPT-Pro consists of 13 high quality tools, accessed through the Illustrator toolbox, with a convenient information toolbox, giving users the familiarity of the Illustrator interface. BPT-Pro not only can display measurements of all or parts of segment dimensioning but also measures free curves.