remm

<p>This plugin provide widget that display a list with categories and posts in your sidebar.<br />
Widget can save the opened categories, and use cache.</p>


Wp Ajax Tree

This plugin provide a widget that display a category and pages tree on your sidebar, using ajax to collapse categories.

damlys

<p>Complete dropdown tree navigation that contain pages, categories with posts, tags, authors and own menu.</p>
<h4>Features and highlights</h4>
<ul>
<li>Whole site in one place</li>
<li>Excluding pages and authors from navigation</li>
<li>Simple widget</li>
<li>4 skins</li>
</ul>
<h4>Translations/Languages</h4>
<p>This plugin is available in your WordPress language on site and in English and Polish in Dashboard.</p>
<h4>Skins</h4>
<ul>
<li>iOS Lion</li>
<li>Windows 8</li>
<li>Windows 7</li>
<li>Windows XP</li>
</ul>


EasyTree

Complete dropdown tree navigation that contain pages, categories with posts, tags, authors and own menu.

Wp Ajax Tree vs EasyTree