There are new videos available in the video series on Blender add-on developments for beginners:
It is completely free and has a GitHub repository with code .
In this module we will refactor the render_done add-on encountered in the previous module into a multi-file add-on. The first video will take a look at why splitting up an add-on might be beneficial for maintenance, reuse and the options to include non-Python files, something we will make use of in the second video where we will add a custom icon to one of the operators.