Can I add another filter option to element index views? What I am trying to do is adjust the entry index page to be more specific for our use case, I have already sorted out extra columns but I want to sort or filter by entry type. Of course I can already sort by typeId using modifyEntrySortableAttributes but this is not ideal.

I either want to be able to sort by an entry type's name using modifyEntrySortableAttributes or better still insert another filter button of all the types in-between the status filter and the search bar, see mock-up below.



Any help greatly appreciated!
I made a small plugin that nests Entry Types under their section in the sources list that might be good enough for what you're after:

https://gist.github.com/mdcpepper/548fd04939e040507960