You are free to download the alpha version* of Family Diagram at any time. Use this form to sign up for an alpha license key which will unlock all features from the professional license. The alpha key will be emailed to you within a couple of days. The alpha key will expire once the Windows version is released.
By requesting an alpha license key you are agreeing to report any bugs that you encounter using the support form linked above.
Support for the Windows alpha version can be found at the usual support page.
While the alpha version of Family Diagram is fully functional and currently offered free of charge, the app will only be available on a paid subscription basis once it is released. A subscription costs $199.99/year or $19.99/month and will support the significant cost of ongoing development.
From that point on you will not be able to use the diagrams you create using an alpha license without first buying a subscription to use the app. However, anyone will be able to download and use the app for a single diagram. You will be able to import any diagram that you created with your alpha version into the free version for viewing and editing, but you won’t be able to save your changes outside of the app. Each time you import a diagram into the free version it overwrites any changes made to your current one free diagram.
*Alpha versions are pre-beta, which means that you should expect bugs where the app does not work as it is intended to. In contrast, a beta version is aimed at evaluating the app’s concepts using a version that works as intended.