CellularAutomaton 1.0 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The application is categorized as Theming Tools.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. This free Mac app is an intellectual property of Eagleeye87 Software.
From the developer:
The screen saver randomly creates anywhere from 1 to 5 ants on a grid and then performs the simple rules for each ant. If you ever wish to save a pattern that appears on your screen simply press the s key. Once you hear a beep, a file starting with CellularAutomaton has been saved to your Desktop.
You may want to check out more software for Mac, such as scarytime v9, Christmas Tree Creator '04 or System47, which might be similar to CellularAutomaton.