A later release of this plugin will enable you to add functionality through your own filters, actions and shortcodes. An extension will also be released to give you an idea of the type of functionality you can add.
Yes, this version has hooks, and the RSS functionality is an extension BUT this was done as proof of concept only; I am still trialing and deciding the most effective easy way for coders to add extensions and shortcodes. Classes/hooks WILL be modified / removed / added / renamed. Any extensions you write for this release probably WON’T WORK in subsequent versions – so hold fire on publishing your category related Twitter feed until I’ve finalised and documented the hooks!