I find it very odd that the author doesnt understand how to work with files and wastes my devices storage space (and my time) by making a copy of every file I want to view. It includes a bunch of rip-off in-app purchases (e.g. pay extra to use Dropbox) and an annoying UI. The app is incredibly slow. Opening a simple scanned page can take MINUTES before you can even work with it. Once opened, navigating pages within the file causes constant delays and no feedback as to why the app appears to be non-responsive. The speed of image handling makes it appear that the author doesn’t know how to use Apple’s imaging code or is using some inefficient public domain stuff.