I tried installing on my recently purchased Android v4 unit (not a tablet, it's a plug-in for the TV using HDMI one end, USB [for mouse] the other end, and needs 1A of power [which I got from a powered USB hub - computer sockets normally have a limit of 500mA [ie 0.5 Amp]). Anyway, this cheap little unit makes my big TV into something similar to a tablet without the portability (!)
Didn't install. I can see from their website that latest changes concern how the verification [by phone number] works, so I assume they're using that as that's an easy way to be sure someone is a friend/relative and not masquerading.
Unfortnately, based on this (automated) response, tablets are down the list:
"Sorry! It seems that you are trying to use a tablet. Unfortunately tablets are not supported. Tablets are not as portable as smart phones.
We are currently focusing on phones before we start adding support for peripheral devices. Your tablet may function currently, or it may have functioned in the past, but we do not provide support for it.
We do our best to make our app work on all phones which may cause problems for other devices.
Thank you for contacting WhatsApp."
There may be some other ways to share data (eg with Dropbox) but not sure many methods are as easy as WhatsApp (I don't use it, personally, but my sister has been using it on her iPhone, and is a 'fan').
Sorry, no good news on this one 