Whether you are creating a New expense or editing an existing one, the Details page will have a Show More button on the top right of the screen.  Once you click this, the Show More Mode will be enabled and additional fields, such as payment method and check number, will be available for your use. 

To view Detail pages, use the ‘Expenses’ button in the left hand navigation bar to access the Expense page.  From here you will be able to choose from a list of existing expenses to edit (blue ‘Edit’ button) or you can create a New Expense by clicking the green ‘+Add’ button.  In both cases, you will be taken to a Details page where the Show More Mode can be enabled.