Spotlight is a better search engine than its interface admits. It indexes contents, dates, kinds, authors, camera models and a few hundred other attributes, and then hands you one text field. HoudahSpot is the window that lets you say what you actually mean: a PDF, containing this phrase but not that one, somewhere under the Clients folder, modified in the last two years, larger than a megabyte. Results appear in a proper list you can sort, refine and preview.
The part worth paying for is templates. Once you have built a nasty query — say, invoices from a particular client in a given tax year — you save it and run it again next quarter by typing one word into the blank. People who do document work end up with half a dozen of these and treat the app as a filing system.
Two honest limits. It is only as good as Spotlight's index, so network shares and some external volumes are out of reach. And it is a searching tool, not an organising one: nothing here moves your files into a better structure.
If macOS search already finds what you need and you search by filename, you do not need this. It earns $39 from people who regularly cannot find a document they know exists.



