Gary Jones

Devin Price

This plugin registers a custom post type for portfolio items. It also registers separate portfolio taxonomies for tags and categories. If featured images are selected, they will be displayed in the column view.
This plugin doesn’t change how portfolio items are displayed in your theme. You’ll need to add templates for archive-portfolio.php and single-portfolio.php if you want to customize the display of portfolio items.

Portfolio Post Type

This plugin registers a custom post type for portfolio items.  It also registers separate portfolio taxonomies for tags and categories.

KrishaWeb

Dilip Bheda

Pratik Gandhi

Girish Panchal

This plugin gives flexibility to user to change posts from one post type to another. Also users can change posts from post type to page.
Features 
• Easy installation 
• Post to other post type or page. 
• Free support
Checkout the advanced features of Post Type Transfer: 
• It provides functionality enable/disable the feature for certain post type. 
• It also provides functionality to transfer the taxonomy while transferring the post to other post type. You can create new taxonomy or use the current one.
<a href="https://codecanyon.net/item/post-type-transfer-pro/21585540" rel="nofollow ugc">Get the Post Type Transfer Pro</a>
<h4>Supported Types</h4>
The plugin will help you to transfer any post’s post type to other post type. It will also allow custom post type. Invisible post types like revision, menu and attachment are purposely excluded

Post Type Transfer

Easy to use

A simple way to change a post's post-type in WordPress

Portfolio Post Type vs Post Type Transfer