Haven't thought of that, but maybe self hosting could be done. I intend to make the app free, but it isn't open source.

Why free if not open source? Because the latter would be a prime requirement for me; the former is not.

I'd love to know as well, in particular your stance with regard to the UI concept itself — which is a very interesting take on a common problem.

Is it your intention to proselytise this particular UI concept (i.e., “Everyone should use this type of calender view! It makes calendering better for everyone. Get inspired and go implement it in your own software!”) or to test the waters for a commercial product?

For me, at least, being able to personally audit, contribute, and maintain the software (even in a case where you stop caring about it) is very important to me.

In any event, looks fantastic and best of luck.

Don't make it free, charge for it. If it's valuable, people will pay for it.