TaskSurfer - TaskSurfer gives you all of the tools you need to manage things the way you want.
DEVONthink - DEVONtechnologies develops DEVONthink, DEVONagent, and other Mac and iOS apps for document and information management and web research.
IDocument - Feel powerless of your documents chaos in your Mac?
HoudahSpot - Advanced File Search Utility for Mac OS X
Invantive BusinessDrive - Invantive BusinessDrive enables you to work with documents stored in (cloud) applications and...
Yep - A creator-friendly search engine