FET is free software (think open source, but better!) that is designed to create timetables, and is authored by Liviu Lalescu and Volker Dirr.
The official website can be found here, and the FET source code (and the FET Windows .exe file) can be downloaded from the official website here.
FET for macOS can be compiled from the source code available on the official website (see the instructions here), or the compiled app can be downloaded from this page by clicking on the button below. New versions will be added as they become available.
When you run FET for the first time, you will get a notice that “fet cannot be opened because the developer cannot be verified.” (it costs $99 USD per year to join the Developer Program, which unfortunately is required for app notarization). In order to bypass this warning, right click (or control-click) on the FET app and select “open”. This step is only necessary the first time you run the app after downloading.
Please report any issues you may have with the Mac version in the FET forums here.
If you want to verify your download, the SHA 256 checksum for the .zip file is
9f37f96b73c33eadb17d19a19790aa71d6516ac02e9eff9379d3a7d6d8ad1dc5
In order to check that the .zip file has been downloaded correctly, you can open the Terminal app on your Mac and then type the following command (adjusting the path to the downloaded .zip file and the FET version number accordingly).
shasum -a 256 /Users/yourusername/Downloads/fet-X.X.X.zip
After executing this command, the Terminal window should show the checksum indicated above.