by Igor Jerosimić on WordPress.org
Allows theme developers to add order/sort functionality for categories, tags and custom taxonomies.

The screenshot of Category section after drag and drop reorder operation.
Plugin can be used for reordering categories, tags and custom taxonomies. This plugin is primarily intended as an aid to theme developers.
Plugin supports multisite installation.
The minimum requirement is that you have at least WordPress 3.5 installed.
Fetching sorted terms from a custom taxonomy will be enabled by default:
$terms = get_terms( 'your-taxonomy-name' );
If you wish to sort by name (disable plugin’s custom sorting) you will have to set ‘i_order_terms’ to ‘false’:
$terms = get_terms( 'your-taxonomy-name', 'i_order_terms=0' );
Plugin adds a new column to the ‘term_taxonomy’ table, make sure to backup your database before installing. Column is removed when you delete the plugin.