Apple, in all their wisdom, decided against an iCloud Drive app on iOS because file managing on a phone or tablet is apparently considered pure evil. So just now I downloaded a PDF file on my work PC and added it to the iCloud Drive Preview folder through iCloud.com. It doesn't show up in iBooks. I tried moving the PDF file to a newly created folder, which doesn't work either. Does anyone have an idea how to access it from my iPhone running iOS 8?