How can I limit the availability of our app to california only

AFAIK, it is not possible to limit to some states. Only country level.

Feel free to post a Feedback for suggestion.

Thanks for your answer... And yes I found, finally, how it is possible to limit it to a country. ( you go: General and below general you click on: Pricing and Availability. On Pricing and Availability you go to: All countries or regions selected there you click on "Edit" Then you can select or deselect the countries.

I would suggested, it should be also possible to limited the availability to a state or even better to a zip code.

why are u doing this

To have a more targeted field of use... Does this answer your question?