content: I think this app does its job. I have had to uninstall it regularly to restore speed on opening large files and lately that doesnt help. I have a manual that is 136 MB and 3120 pages. It takes 12 seconds to open and 8 seconds for the contents to show. Then added time up to 12 seconds to display new pages. I can open it in Google drive it takes 10 seconds to scroll to the bottom then instantly displays any page in the book. Unfortunately it doesnt support bookmarks. Years of this behavior.