Now, we have it!
Starting from Version 2.12.491, you can exchange documents with your contacts! Both of you should have at least version 2.12.491 installed for this to work. For now, only PDFs can be exchanged. I am fairly certain that the other document types will be added when the final version is published on the Play Store.
1)Select the user you want to share document
2)Click the icon on th top right coner close to call icon
4)Select the document to the transferred.