Will my app work with an unpublished theme?
Yes. All Store Bricks apps are prepared to work on all themes, no additional configuration is required.
However, though our app effect is meant to activate on all themes once installed and enabled, its configuration is global. This means that whatever is set on the app preference page, it'll apply to all your themes, including the published and the published ones. Therefore, if the app does not to display as expected on your unpublished theme, it's because the app is giving priority to your live theme, telling the app where to apply the effect based on the public theme html.