Web Android application code for word-press website

Hi support,
I have a WordPress blogging website and 2 websites with different sub-domain.
I want to design a web android application software for it, which has been done using the kotlin language. So that in future I can change the code and manage it by myself.
Could you please help me if you have any code for my above requirement so that i want to purchase it.

WordPress offers free/paid native apps, you can use those instead