You can add more subcategories, and customize the categories as you wish.
Settings > Income or Expense Category Management
For example, you want to add "Medicine" under Health; the main category.
1. Tab the Health; main category.
2. Tab the '+' button on the detail page.
3. Type "Medicine" and save.
4. You will see "Medicine" has added under the "Health".
5. You can also change the sort order in sub-categories.
6. On the Entry page, you can find the "Medicine" item.
Also, you can access the edit page via the pencil button.