On the last months I've been working on WhatsApp protocol. After releasing an sniffer for wireshark now I've developed a working plugin for Pidgin (well, actually anything that uses libpurple).
The plugin is capable of thefollowing features:
Things that need to be done:
Some screenshots running in Linux:
Here is the last update of the plugin. Looks promising, and works!
Here running on my old Windows. You can create groups and invite people just like the official client.
This is all for now, keep an eye on it. The sources are available at the usual place: