The latest update for PDFpen, PDFpenPro, and PDFpen for iPad adds folder support (1 level deep) for iCloud syncing. I manage a lot of PDFs and I really dig PDFpen’s iCloud sync. The addition of folders makes it possible for me to go from managing 10 documents to managing 100. I haven’t got there yet but will consider it an iCloud stress test when I do. Stay tuned. By the way, I haven’t posted yet on how I use PDFpen for iPad and how much I love it but expect something in the not so distant future.