Why create a graphical interface?
Building an interface will let other users interact with the code in a more accessible and friendly fashion, by entering or choosing the values for the set of parameters you make available to them.
Creating an interface:
First, adapt your code to accept command-line parameters. Remember that some users may run your code directly from the Code tab, so please provide sensible defaults.
Second, navigate to the Interface tab and begin designing. Start by selecting the type of parameter you'd like to add on the bottom left. It can be a text field, a drop-down list of pre-defined values, or an input file selector. Configure the parameter and click Save, repeating these steps as needed.
Third, click Run and wait for the run to finish. When you've done so, click Add Result File and select the result file you'd like displayed in the Results pane every time an Interface run finishes. Finally, click Save.
Repeat this for any result files you want the user to see.
Accessing an interface:
Click the "Interface" tab on the top right of a capsule. Remember that not all authors will have created one.