Have you tried using the iOS share extension?
Insert the iXpand Drive.
Go to Whatsapp
Select the media files from the group chat / individual chat section
Press the “up arrow” button and this will bring up the native share options (with facebook, twitter, email etc.)
In this list, you should also find the iXpand Drive app. Select iXpand and then save.
See more here.
http://kb.sandisk.com/app/answers/detail/a_id/19291/kw/share%20extension
