Michael Henke

This plugin is including the Flattr button for your blog inside a widget. 
This way the button can be easily positioned in any of your themes sidebars.
Your flatter credentials are all automagically imported from the official Flattr plugin.

Flattr Widget

This plugin is including the Flattr button for your blog inside a widget.

eewee

Use the system “flattr” your worpdress website.
Shortcode for :
<ul>
<li>Add Widget flittr</li>
<li>Add big button with counter (coming soon)</li>
<li>Add small button with counter (coming soon)</li>
<li>Add static button (coming soon)</li>
<li>Add Code QR (coming soon)</li>
</ul>
More informations <a href="https://flattr.com" rel="nofollow ugc">flattr</a>
PS: question, <a href="http://www.eewee.fr" rel="nofollow ugc">eewee.fr</a>.
<ul>
<li>See the <a href="https://wordpress.org/extend/plugins/eewee-flittr/changelog/" rel="ugc">Changelog</a> for what’s new.</li>
</ul>

eewee flattr

Use the system "flattr" wordrpess on your site.

Flattr Widget vs eewee flattr