This app doesnt work properly. I installed my EX4 added couples of pictures and folders and everything worked well so I added more pictures (62k) and since that time nothing shows on the apps; I just get that stupid waiting wheel forever. I read a lot on the WD community so I: rebooted my NAS, restarted it, rebuilt it, rescanned it, deleted the app, reinstalled it and still nothing. This is a huge deception coming from a supposedly "well established business and renowned in storages" that cannot built two basic apps; because MC Cloud app is as bad since it cannot show thumbnails and cannot save picture on the Camera roll.
WD should fix its apps ASAP or leave that business to other players.