OK, I wanted to make use of the Image Converter Plugin by Seehat together with the post file upload hook (See this thread). Reading on the Post file upload hook on GitHub, Bastian posted this:
We are currently working on a global hook system. So I’m afraid I have to finally close this.
Is there already a hook like this in the current Beta 2.1? Or otherwise, can I still use this upload-hook?
My purpose is to use the Image Converter Plugin multiple times after a file has been uploaded, to create multiple Image-Sizes for a responsive layout.