remm

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

Wp Ajax Tree

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

FAKTOR VIER

<a href="https://www.f4dev.ch" rel="nofollow ugc">F4 Post Tree</a> adds a neat and easy to use sidebar tree view to your posts and/or pages backend.
Once activated, your posts/pages will be displayed hierarchically in the tree sidebar.
The sidebar appears on every post related page in WordPress, so you don’t have to leave your current page to manage or sort the posts/pages.
For every post status there is a icon color, so you can see if a post/page is published, draft or planned.
You can also see if someone else is currently editing a post. In this case a small lock-icon appears in the tree.
This Plugin is currently not compatible with Multisites. This feature will be added in the near future.
<h4>Usage</h4>
This plugin works out-of-the-box. By default, the tree will be displayed for both pages and posts. You can enable/disable the tree for both individually on the settings page (Settings -> F4 Post Tree).
<h4>Features overview</h4>
<ul>
<li>Tree view sidebar for pages and posts backend</li>
<li>Hierarchical order and display</li>
<li>Drag and drop sorting</li>
<li>Colorful icons for every post status</li>
<li>Displayed on list view and edit page</li>
<li>Lock symbol for posts that are currently locked by another user</li>
<li>Automatically refresh if another user edits a page</li>
</ul>
<h4>Planned features</h4>
<ul>
<li>Context menu for quick actions</li>
<li>Multisite compatibility</li>
<li>More tba</li>
</ul>
<h4>Upcoming PRO version</h4>
We’re working on a extended PRO version for this plugin, which adds a few neat features:
First of all, it adds support for custom post types.
But the most interesting feature is the support for menus. With this feature you can manage and sort the menus you want directly in your tree sidebar.
That means, you can activate every menu you want to be shown in the tree, so you can drag&drop posts directly at the position you want the post to appear in the menu. You don’t have do add/remove/sort posts and pages through the awkward menu page (Display -> Menus).
This feature improves the handling for menus drastic. Your editors and authors will love this!
If you are interested in this neat fetures, you can write us an <a href="mailto:hallo@faktorvier.ch?subject=I'm%20interested%20in%20F4%20Post%20Tree%20PRO!&body=Please%20notify%20me%20if%20the%20PRO%20version%20is%20available!" rel="nofollow ugc">email</a> to get notified when the PRO version will be released.

F4 Post Tree

This plugin adds a neat and easy to use sidebar tree view to your posts and pages backend.

Wp Ajax Tree vs F4 Post Tree