Determine the cost of developing an Android app

1. I have an app idea that I like and that I think can make some profit, so we'll sign an NDA (pure formality) to start with.
2. Then I will give you three files : 1) the development terms of reference, 2) an explanation of the formula, and 3) a HI-fidelity prototype in Adobe XD
3. By examining these three documents you will have to determine the cost of its development as accurately as possible, step by step.
4. At the end of the document of terms of reference there are items in front of which you need to write the cost, but please if you are an expert most likely you will expand this list.
5. Do not forget to explain the cost of each item.

In fact, the idea is trivial and there are a lot of such applications in the Play Market. But I'm an experienced UX/UI designer and I know for sure that the success of an app is not because of the idea, but because of the development team and empathy towards its audience. So if it works out, I wanted to continue my working relationship with you.

Additional information:
1. I don't know English very well, so please feel free to write me if you don't understand something.
2. Kotlin knowledge is a priority, but not the deciding factor.