Let PerfectViewer read/download comics from Google Drive, Dropbox, OneDrive, Amazon Cloud Drive and box.
Support USB OTG.
Need install Perfect Viewer 2.7.1+
-Fixed: Could not access Google Drive.
-Support Perfect Viewer backup/restore function
-Remove amazon cloud drive. Because amazon not allow 3rd party app access anymore.
-Fixed could not login Microsoft onedrive
-Fixed could not login amazon cloud drive
-Added : Support USB OTG device even if system not support it.
Fixed can't use Google Drive under Android 6.0+. Now will request permission at runtime.