Download of PairProgram 1.2 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free Mac app is a product of Foucauld Degeorges. The application lies within Developer Tools, more precisely Webmaster Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
PairProgram is a tray icon application that lets you start a pair programming session. All you need to do is configure a number of rounds and the duration of each round, hit Start and code away. The app will ring when it is time to switch the keyboard.
Pair programming is popular in agile software development.
You may want to check out more Mac applications, such as Browsealoud, solr or joomla-, which might be similar to PairProgram.