Yep, that PDF option for the App is already on there too. It's a bit more tricky with iOS than Android, but there are some extensions that should be able to be used to access storage like Dropbox, Google Drive, Box, etc. Also, there is the possibility of a folder in app that would support this.
Better yet, it would be better to add them to your online account and then after an update, have them accessible via the app and even categorized. Stay tuned.