Implementation of mobile app to connect it to extend server

I need help implementing Android mobile app. I have a linked list server I want this app to be the front end to it.

The idea of the server is to mimic blockchain system but we will give the patient the control of the data

we need two users
1- Patient:
Register with his password that will be save to our server. we linked this patient is to hash id that will show the data in DB encrypted
Save health data such as :
Heartrate , Oxygen level, movements , temperature..
we need a Data control page
patient can :
Add these data and choose if the data should be Immutable, editable or RTBF( which means we can delete it )
Patient request add, edit , delete in this page
Patient have notification from the doctor about test results and diagnosis

2- Doctor as a user
Doctor page should have the list of the patients
Ask to see the patient data by notify the patient and after the patient accept the doctor see the data
Send his diagnosis

I attached: 1- server implementation in Java
2- mobile application that I just start and I need help to accomplish what I described above.


Please let me know if you can help