Custom Footer View?

Is there a way to add a custom footer view (such as a "load more" cell) to the end of the list in certain situations?

I need to add a full width cell (that doesn't scroll horizontally with the rest of the table) when more data needs to be loaded in and cant figure out how to add this in.

Any help would be appreciated.
Thanks

No file, test, or entry point is named. Start by locating the library's table and cell-layout extension points, then determine how a full-width footer or load-more cell could remain outside horizontal scrolling; done means the requested footer behavior is supported or its limitation is clearly documented.

Written by the indexing model from the issue text.