Scott Reilly

This plugin adds “← Previous” and “Next →” links to the “Edit Post” admin page if a previous and next post are present, respectively. The link titles (visible when hovering over the links) reveal the title of the previous/next post. The links link to the “Edit Post” admin page for the previous/next posts so that you may edit them.
By default, a previous/next post is determined by the next lower/higher valid post based on the date the post was created and which is also a post the user can edit. Other post criteria such as post type (draft, pending, etc), publish date, post author, category, etc, are not taken into consideration when determining the previous or next post.
Users can customize how post navigation ordering is handled via the “Screen Options” panel available at the top of every page when editing a post. A dropdown presents options to order navigation by: ‘ID’, ‘menu_order’, ‘post_date’, ‘post_modified’, ‘post_name’, and ‘post_title’. Post navigation can further be customized via filters (see Filters section).
NOTE: Be sure to save the post currently being edited (if you’ve made any changes) before navigating away to the previous/next post!
Links: <a href="http://coffee2code.com/wp-plugins/admin-post-navigation/" rel="nofollow ugc">Plugin Homepage</a> | <a href="https://wordpress.org/plugins/admin-post-navigation/" rel="ugc">Plugin Directory Page</a> | <a href="https://github.com/coffe2code/admin-post-navigation/" rel="nofollow ugc">GitHub</a> | <a href="http://coffee2code.com" rel="nofollow ugc">Author Homepage</a>
<h3>Filters</h3>
The plugin is further customizable via six filters. Such code should ideally be put into a mu-plugin or site-specific plugin (which is beyond the scope of this readme to explain).
<h4>c2c_admin_post_navigation_orderby (filter)</h4>
The ‘c2c_admin_post_navigation_orderby’ filter allows you to change the post field used in the ORDER BY clause for the SQL to find the previous/next post. By default this is ‘post_date’ for non-hierarchical post types (such as posts) and ‘post_title’ for hierarchical post types (such as pages). If you wish to change this, hook this filter. Note: users can customize the post navigation order field for themselves on a per-post type basis via “Screen Options” (see FAQ and screenshot for more info).
Arguments:
<ul>
<li>$field (string) The current ORDER BY field</li>
<li>$post_type (string) The post type being navigated</li>
<li>$user_id (int) The user’s ID</li>
</ul>
Example:
<pre><code>/**
 * Modify how Admin Post Navigation orders posts for navigation by changing the
 * ordering of pages by 'menu_order'.
 *
 * @param string $field The field used to order posts for navigation.
 * @param string $post_type The post type being navigated.
 * @param int $user_id. The user's ID.
 * @return string
 */
function custom_order_apn( $field, $post_type, $user_id ) {
 // Only change the order for the 'page' post type.
 if ( 'page' === $post_type ) {
 $field = 'menu_order';
 }

 return $field;
}
add_filter( 'c2c_admin_post_navigation_orderby', 'custom_order_apn', 10, 3 );
</code></pre>
<h4>c2c_admin_post_navigation_post_statuses (filter)</h4>
The ‘c2c_admin_post_navigation_post_statuses’ filter allows you to modify the list of post_statuses used as part of the search for the prev/next post. By default this array includes ‘draft’, ‘future’, ‘pending’, ‘private’, and ‘publish’. If you wish to change this, hook this filter. This is not typical usage for most users.
Arguments:
<ul>
<li>$post_statuses (array) The array of valid post_statuses</li>
<li>$post_type (string) The post type</li>
</ul>
Example:
<pre><code>/**
 * Modify Admin Post Navigation to allow and disallow certain post statuses from being navigated.
 *
 * @param array $post_statuses Post statuses permitted for admin navigation.
 * @param string $post_type The post type.
 * @return array
 */
function change_apn_post_status( $post_statuses, $post_type ) {
 // Add a post status.
 // Note: by default these are already in the $post_statuses array: 'draft', 'future', 'pending', 'private', 'publish'
 $post_statuses[] = 'trash';

 // Remove post status(es).
 $post_statuses_to_remove = array( 'draft' ); // Customize here.
 if ( 'page' === $post_type ) {
 $post_statuses_to_remove[] = 'pending';
 }
 foreach ( $post_statuses_to_remove as $remove ) {
 if ( false !== $index = array_search( $remove, $post_statuses ) ) {
 unset( $post_statuses[ $index ] );
 }
 }

 return array_values( $post_statuses );
}
add_filter( 'c2c_admin_post_navigation_post_statuses', 'change_apn_post_status', 10, 2 );
</code></pre>
<h4>c2c_admin_post_navigation_post_types (filter)</h4>
The ‘c2c_admin_post_navigation_post_types’ filter allows you to modify the list of post_types used as part of the search for the prev/next post. By default this array includes all available post types. If you wish to change this, hook this filter.
Arguments:
<ul>
<li>$post_types (array) The array of valid post_types</li>
</ul>
Examples:
<pre><code>/**
 * Modify Admin Post Navigation to only allow navigating strictly for posts.
 *
 * @param array $post_types Post types that should have admin post navigation.
 * @return array
 */
function change_apn_post_types( $post_types ) {
 return array( 'post' );
}
add_filter( 'c2c_admin_post_navigation_post_types', 'change_apn_post_types' );



/**
 * Modify Admin Post Navigation to disallow navigation for the 'recipe' post type.
 *
 * @param array $post_types Post types that should have admin post navigation.
 * @return array
 */
function remove_recipe_apn_post_types( $post_types ) {
 if ( isset( $post_types['recipe'] ) ) {
 unset( $post_types['recipe'] ); // Removing a post type
 }
 return $post_types;
}
add_filter( 'c2c_admin_post_navigation_post_types', 'remove_recipe_apn_post_types' );
</code></pre>
<h4>c2c_admin_post_navigation_prev_text (filter)</h4>
The ‘c2c_admin_post_navigation_prev_text’ filter allows you to change the link text used for the ‘Previous’ link. By default this is ‘← Previous’.
Arguments:
<ul>
<li>$text (string) The ‘previous’ link text.</li>
</ul>
Example:
<pre><code>/**
 * Changes the text for the 'previous' link to 'Older' output by the Admin Post Navigation plugin.
 *
 * @param string $text The text used to indicate the 'next' post.
 * @return string
 */
function my_c2c_admin_post_navigation_prev_text( $text ) {
 return 'Older';
}
add_filter( 'c2c_admin_post_navigation_prev_text', 'my_c2c_admin_post_navigation_prev_text' );
</code></pre>
<h4>c2c_admin_post_navigation_next_text (filter)</h4>
The ‘c2c_admin_post_navigation_next_text’ filter allows you to change the link text used for the ‘Next’ link. By default this is ‘Next →’.
Arguments:
<ul>
<li>$text (string) The ‘next’ link text.</li>
</ul>
Example:
<pre><code>/**
 * Changes the text for the 'next' link to 'Newer' output by the Admin Post Navigation plugin.
 *
 * @param string $text The text used to indicate the 'next' post.
 * @return string
 */
function my_c2c_admin_post_navigation_next_text( $text ) {
 return 'Newer';
}
add_filter( 'c2c_admin_post_navigation_next_text', 'my_c2c_admin_post_navigation_next_text' );
</code></pre>
<h4>c2c_admin_post_navigation_display (filter)</h4>
The ‘c2c_admin_post_navigation_display’ filter allows you to customize the output links for the post navigation.
Arguments:
<ul>
<li>$text (string) The current output for the prev/next navigation link</li>
</ul>
Example:
<pre><code>/**
 * Change the markup displayed by the Admin Post Navigation plugin.
 *
 * @param string $text The text being output by the plugin.
 * @return string
 */
function override_apn_display( $text ) {
 // Simplistic example. You could preferably make the text bold using CSS.
 return '' . $text . '';
}
add_filter( 'c2c_admin_post_navigation_display', 'override_apn_display' );
</code></pre>

Admin Post Navigation

Adds links to navigate to the next and previous posts when editing a post in the WordPress admin.

ambrosite

IMPORTANT: Make sure you are using the right plugin.
<ul>
<li>Next/Previous Post Link Plus is intended for use in single post templates.</li>
<li>Next/Previous Page Link Plus is intended for use in page templates.</li>
</ul>
The two plugins have similar sounding, but different, function names. If you mistakenly install the wrong plugin, you will get a “call to undefined function” error. If you want to create next/previous links for your pages, please check out: 
https://wordpress.org/extend/plugins/ambrosite-nextprevious-page-link-plus/
IMPORTANT: This plugin is not compatible with PHP 4. If you try to install it on a host running PHP 4, you will get a parse error. WordPress has officially ended support for PHP 4 as of version 3.2, so you should upgrade to PHP 5.2 now. For those who cannot upgrade, you can download the alternate PHP 4 compatible version of the plugin. The only difference with the PHP 4 version is that the %category variable will not work with custom taxonomies. 
http://www.ambrosite.com/download/ambrosite-nextprevious-post-link-plus.php4.zip
This plugin creates two new template tags — next_post_link_plus and previous_post_link_plus — which are upgraded versions of the core WordPress next_post_link and previous_post_link template tags. The new tags include all of the functionality of the core tags, plus the following additional options:
<ul>
<li>Sort the next/previous post links on columns other than post_date (e.g. alphabetically).</li>
<li>Sort next/previous links on custom fields (both string and integer sorts are supported).</li>
<li>Full WordPress 3.3 compatibility, including support for custom post types, custom taxonomies, and post formats.</li>
<li>Loop around to the first post if there is no next post (and vice versa).</li>
<li>Retrieve the first/last post, rather than the previous/next post (for First|Previous|Next|Last navigation links).</li>
<li>Display post thumbnails alongside the links (WordPress 2.9 or higher).</li>
<li>Truncate the link titles to any length, and display custom text in the tooltip.</li>
<li>Display the title, date, author, category, and meta value of the next/previous links.</li>
<li>Specify a custom date format for the %date variable.</li>
<li>Restrict next/previous links to same category, taxonomy, format, author, custom field value, custom post ID list, or custom category list.</li>
<li>Exclude categories, custom taxonomies, post formats, or individual post IDs.</li>
<li>Three category exclusion methods for greater control over the navigation stream.</li>
<li>Return multiple next/previous links (e.g. the next N links, in an HTML list).</li>
<li>Return the ID, title, date, href attribute, or post object of the next/previous links, instead of echoing them to the screen.</li>
<li>Return false if no next/previous link is found, so themes may conditionally display alternate text.</li>
<li>Works with Post Types Order and other popular post reordering plugins.</li>
</ul>
Extensive documentation on configuring the plugin may be found here: 
http://www.ambrosite.com/plugins/next-previous-post-link-plus-for-wordpress

Ambrosite Next/Previous Post Link Plus

Has many options to customize as well.  Hasn't been update for a while, but still works perfectly with WP 4.5.3.



Excellent - does what it says.

Provides next/previous post link template tags that work the way you'd expect the built-in WP functions to work!



A beautiful thing

This plugin has saved me countless hours and does exactly what it needs to do with easy setup and lots of options. Love it.

Highly recommended

Upgrades the next/previous post link functions to reorder or loop adjacent post navigation links, display post thumbnails, and customize link format.

Admin Post Navigation vs Ambrosite Next/Previous Post Link Plus