There are many software projects that are open source but do include licensing terms. ShofarNexus is simply public domain.
When you have the program, you have the source as it is an integral part of the program.
You are free to do as you desire.
The only request is that you use a different name.
It could be “ShofarOther” to show a relationship to ShofarNexus, or simply “Other”.
You are free to set your own licensing terms.
You are free.