It doe work I have a wd passport ultra. The note 4 software recognises it no problem. Format it in exfat I think and use a otg cable or adapter. Word of warning eject your hard rive otherwise it won't recognise the hard drive
I managed to connect and write to a 1tb toshiba portable and no wxternal power. However I cant do it with a 2tb harddrive WD ultra. Can anyone please help. ES work but you can write