Download the macOS beta – Version 1.0 (161). It requires macOS 12.0 Monterey. Extract the ZIP file and put the extracted app in your “Applications” folder.
The beta is work-in-progress and breaking changes might be introduced. Make sure to back-up your files. You can also use the built-in features to export your data to other formats.
The beta expires. The expiry date is indicated in the “Maparoni” menu item. Make sure you switch to the latest beta, to keep using the app. Maparoni checks on launch, if there’s a new beta available or you can use the “Check for Updates” menu item.