I like to build an app for people who read books. I have a list of people with their detaisl on sheet1, books and details on sheet2, Genre on sheet3.
The most important one: BooksRead/ sheet4. Here I keep trac of who read what book and what the rating and comments are.
My app shows two entries:
1 People: When I select a person I see the detaisl of that person and the books he has read with his comments.
2 Books: When I select a book I like to see the details and a list of people who have read those books.
As a cherry on the ice I like to show the most popular books and the best average rankings.