You can add items with the buttons on the right of the app. To save a configuration, write a name in the "Configuration name" field, and click on the +. To modify the value of a fan, you must select it in a Control item (the left column), select a Behavior, and activate the swtich.
Note: After installation, you will need to add the necessary udev rule to your system for this to work. See the GitHub page for more details.