With the release of Semplice 5, you can now set how your custom JavaScript will behave during page transitions while Single App mode is enabled.
You can adjust these behaviors under "Customize" > "Advanced" > "Custom JS".
Execute Once (default)
This means the custom JavaScript gets executed only on the first visit of the site. If you plan on having the javascript only run once, this would be your best option.
Keep in mind, if you are using Static Site mode the JavaScript will re-load on each page load.
Execute after each page transition
With this option enabled, custom JavaScript will re-load again after each page transition in Single App mode.
This is ideal if you wish to use Single App mode, but need your JavaScript code to execute after each page load.