Download of ThemeChanger 0.6.1 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. The software lies within Theming Tools, more precisely Themes.
This free Mac app was originally designed by The ThemeChanger Project. The app's installation file is generally known as themechanger-0.6.1.dmg. The most popular version of the application is 0.6. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
ThemeChanger is an application that switches your theme in MacOS X. It supports the .theme and .dlta formats, and generates an aqua backup automatically. You can also restore the aqua backup via single-user mode, if an installed theme damages your system.
You may want to check out more Mac applications, such as MeV, VirtualFireplace or Collection for Keynote, which might be similar to ThemeChanger.