It requires development of a simple Android application.
This should be structured in a manner similar to this application:
[url removed, login to view]
The interface should be user-friendly for me and I will insert the contents present in it, and for those who will download and will use the application.
The categories must necessarily be arranged in alphabetical order (A-Z).
For anyone interested, I have created a tree diagram that best explains how the application should be structured.