The latest releases of the phenomenally-popular messaging applications has started adding support sending and receiving documents using their acclaimed Messenger application.
WhatsApp is starting with PDF, as their latest release for Android makes clear.
Sending a document on WhatsApp is quite easy - tap on the attachment icon on any chat and select the new blue Document icon.
ZDnet says that an update for iOS, dated February 28, doesn't mention PDF-sharing per se, but refers to photos and videos.
Learn more via WhatsApp's own FAQ page.