
WhatsApp has been working on an AirDrop-like feature, called Nearby Share, since at least January, and it was meant to come to Android devices first. As of this writing, that feature has not yet been released to the public.
It sounds like the messaging app is looking to bring the feature to iPhones as well, as reported by 9to5Mac. The feature was found by WABetaInfo in the lastest beta version for iOS.