ThemePark 4.1 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. Commonly, this application's installer has the following filename: themepark-4.1.zip.
The most popular version among ThemePark for Mac users is 4.1. The software lies within Theming Tools, more precisely Multiple Desktops. The bundle id for this application is com.geekspiff.themepark. This free software for Mac OS X was originally created by geekspiff. 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:
Use ThemePark to create or modify the way Mac OS X looks, as well as to change the appearance of individual applications. Just draw titlebars, buttons, and other widgets in the graphics editor of your choice, and move them into ThemePark to create a new theme or modify an existing one. Also use ThemePark to safely apply themes to your operating system.
You may want to check out more software for Mac, such as Darwinia, which might be similar to ThemePark.