Plug into possibility
Add new features or connect your favorite tools with thousands of plugins — available on all paid WordPress.com plans.
flattr
3 plugin
eewee flattrUse the system "flattr" wordrpess on your site.
Sexy RSS FooterSexy RSS Footer enables you to add any possible content at the end of every feed entry. This includes variables like number of comments, author etc.
Flattr Shortcode WidgetEasily add custom Flattr widgets to your posts and pages using shortcodes!