Simple Android App and the code

I want to make a simple application where you can request appointments. I want to do it with a free host, for example is [login to view URL] and have the code made with Android studio. The application will have 8/9 screens and a "navigationview" which are: opening screen where you can select between registering or logging in, registering, logging in, a screen with 3 button-type images to request appointments in the different departments, when you Click on one of the previous images to access a next screen to request an appointment where only a calendar will appear and a time to be selected, a screen where you can see the different reserved appointments (and if you do not have any, ask if you want to make an appointment and if you give that if you redirect to the screen with the 3 images if you say no, do nothing), a screen about us where I'll put the text when I have the code, and a screen when you give to close session to evaluate with a question of what you think of the app and some stars and do botone "value" or "No, thanks." If we agree, I send you more information with the design of the different screens. How much it will cost and in how much time does it take to do it? Thank you.