The purpose of Form Builder CRUD is to provide a permanent storage mechanism for the Form Builder module.
This is an API only module. See Form Builder Field for an example implementation.
The Drupal 6 version of this module is unsupported.
After enabling this module, go to Administer > Build > Form builder and you will see an empty table. Click on Add to start creating your form.
Once your form is created and saved, you will see it populating the table, from where you can administer it.
To actually access the form, call the following line from your module:
$form = form_builder_crud_form_load($form_id);
$form['#submit'] = 'my_submission_function';
$form_id is the ID of the form you created with the drag-drop interface and 'my_submission_function' should be an actual submission function that you have previously programmed. Now you should be able to treat the
$form as any other Drupal form in your website.