From the FAQ at the bottom

> Why not open source the app? > > Maintaining an open-source project can be a significant amount of work and I'm not going to have the time to take on such responsibilities. Furthermore, open-sourcing full products tends to result in many clones being sold directly to unsuspecting customers which is not something I want to enable.

It's strange how both of those statements are incorrect... open-sourcing a project allows for contributors to pick up some of the workload and certain licenses would prevent clones from being sold to unsuspecting customers