This is a spin of: how to create child WordPress plugin
I am using a plugin that I use and like a lot, but there is a feature that I need and it seems like the author is busy with life. I am a PHP developer so I could hard code my feature to his plugin, but this way on the next update I will not be able to update without loosing my changes. I have seen that there are some plugins out there that are addons/child to other plugins and they will not work unless you have the main/mother plugin installed.
So my question is what is best to do in this situation? What steps I should take to make sure that after updating the main plugin my child plugin will still work?