Ben Balter

This plugin will work, “as is”, out of the box, but assumes some level of CSS and developer customization to adapt to your site’s specific needs.
Styles can be overridden via your theme’s style.css
Functionality can be overridden via your theme’s functions.php
”Examples”
Don’t display metabox on “product” post type:
<pre><code>add_filter( 'display_custom_fields', 'bb_no_product_metabox' ); function bb_no_product_metabox( $true, $post ) { if ( $post->post_type == 'product' ) return false; return true; } </code></pre>
Don’t display the product_id metakey
<pre><code>add_filter( 'dcf_postmeta', 'bb_no_product_id' ); function bb_no_product_id( $postmeta ) { unset( $postmeta['product_id'] ); return $postmeta; } </code></pre>
Don’t display metabox title
<pre><code>add_filter( 'dcf_heading', '__return_false' ); </code></pre>
Display metabox below content (rather than floated to the right)
<pre><code>add_filter( 'dcf_before_content', '__return_false' ); </code></pre>

Display Custom Fields

Inserts a Wikipedia-like metabox into posts with all the post's associated custom fields and taxonomy terms.

Andrew Norcross

tripflex

Creates a panel to change or delete meta keys in bulk. Useful for when you are switching plugins or themes that use specific meta keys for functionality, or for general cleanup for older sites that may have older meta data that is no longer in use.

Post Meta Manager

A simple utility plugin for changing or deleting post or user meta (custom fields) keys in bulk.

Display Custom Fields vs Post Meta Manager