Bjango's iStat Menus 4 does a better job than the competition when it comes to showing you what's going on inside your Mac.
Eye-Friendly's keyboard shortcuts and multiple-display support make it a nice resolution switcher for Retina MacBooks.
If you need to display and update data on a regular basis with a minimum of difficulty, it's unlikely that you'll find anything better at handling that task than Status Board.
If you find OS X's built-in capabilities for unarchiving and uncompressing files to be too limited, you'll want to check out Dag Agren's free The Unarchiver.
Lost Photos helps you find photos, received via email, that have gotten lost in your ever-growing archive of old messages.
Printopia Pro, an enterprise version of the popular OS X utility, aims to expand support for Apple's AirPrint to large and small organizations, all at less than the cost of a single new printer.
Is your cordless phone causing interference issues with your AirPort network? Change your phone rather than your AirPort settings.
Macpaw's catch-all utility offers scanning and cleanup of accumulated fluff—generally unused files and applications—on your Mac.
Drafts 3.0 adds a lot of organization to the popular iOS app for creating and repurposing text notes. Lex Friedman has a first look.
Cordless Dog's Stay ensures your windows stay where you want them. It's a useful utility for Mac users who switch between multiple monitor configurations, such as MacBook owners who connect to an external display.