The 2.3.1 version of Chordology for Mac was available to download on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. Chordology for Mac is categorized as Education Tools. This free software for Mac OS X is an intellectual property of The Great Magnet Ltd.
From the developer:
Chordology is a multi-instrument chord dictionary allowing you to access thousands of chords. The application includes chords for multiple instruments, including guitar, piano, and ukulele. It shows thousands of variations of each chord. The tool supports iPhone, iPad, and OSX.
You may want to check out more Mac applications, such as ChordPhobia, Learn To Draw or EarMaster Essential, which might be related to Chordology.