Dave Bergschneider

Intuitive Category Checklist makes selecting categories easier for sites with a large amount of categories and sub-categorization. This plugin works in both quick edit mode and stand full post mode.
Related Links: <a href="http://www.crunchingpixels.com/portfolio/2011/07/intuitive-category-checklist/" title="Intuitive Category Checklist Plugin for WordPress at Truimage Productions" rel="nofollow ugc">Plugin Homepage</a>.
This release has been tested compatible with all WordPress versions since 3.1
Please submit feedback to the plugin’s home page in regards to features you would like to see in the future.
<h3>License</h3>
Good news, this plugin is free for everyone! Since it’s released under the GPL, you can use it free of charge on your personal or commercial blog. If you have found this plugin to be useful plese give it a rating or you can thank me and leave a <a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=39WPEFFWFDXTL" title="Donate with PayPal" rel="nofollow ugc">small donation</a> for the time I’ve spent writing and supporting this plugin.

Intuitive Category Checklist

Adds expanding/collapsing functionality to the categories checklist inside posts.

Kharis Sulistiyono

Dropdown hierarchical category in WordPress post write panel or editing screen. It makes the categories or taxonomies list in a better UI which enables show/hide toggle of child categories. It comes with plugin settings page where you can select in what custom post type(s) the dropdown UI will be applied to.
The idea comes from default WordPress hierarchial post categories which looks not good. Imagine that there are a lot of child categories. After selecting child category then publishing or updating a post, the arrangement seems not pretty — the child categories moved away from its parent. This plugin tackles that situation.

WP Dropdown Hierarchical Category UI

It makes the categories or taxonomies list in a better UI which enables show/hide toggle of child categories. Supports any custom post types.

Intuitive Category Checklist vs WP Dropdown Hierarchical Category UI