I used to be able to add a pdf on my iphone or any of my ipads using the “share” button and then clicking on the DTTG blue-ish symbol. After that it asked my the database I wanted to use, I confirmed one and pressed the done-button on the upper right corner.
Next I saw that newly added pdf in the inbox of the database selected earlier.
it used to work. but these days I can no longer find my pdfs there nor anywhere else on the database. I even created a new database to see where the pdfs might have vanished to… nowhere… and certainly noplace after syncing to find them on DT3…
… please advice 
thnx
Chris