Official !OnionCat information can be found at the [https://www.onioncat.org/ OnionCat Primary Site] and on the [https://www.cypherpunk.at/tag/onioncat cYpherpunK blog].
There are also some docs at [https://www.cypherpunk.at/ocat/download/Docs/ OnionCat Docs] and in the [https://www.cypherpunk.at/onioncat_trac/ Trac wiki].
Through Tor at the [http://kpvz7ki2v5agwt35.onion/wiki/index.php/Main_Page Hidden Wiki] it is possible to get !OnionCat...