Our website provided a free download of IDImposer 2016.11.18 for Mac. The software lies within Productivity Tools, more precisely Office Tools. This software for Mac OS X is a product of Sterling Computing.
From the developer:
InDesign-based tool for directly producing imposed PDF files of your saddle stitch booklets, newsletters, and pamphlets, as well as perfect bound books, cut stack sheets, sheets of business cards and labels, and much more. It is fully compatible with the newly released InDesign CC 2017.
You may want to check out more software for Mac, such as PitStop Extreme, FileOpenInstaller or Blurb Tally, which might be similar to IDImposer.