Is there an extension or component that can (via the ComponentToImage extension) make the background of a PNG image transparent?
as far as I know, there is no such extension available…
but probably an extension developer is interested in providing that functionality?
alternatively you could write your own extension and create the functionality yourself…
more information about how to create an extension see the App Inventor Extensions document
however that will be more advanced and will require some Java skills…
PS: I moved your thread into the #marketplace Request category