Stephanie Leary

This is a utility for converting lots of posts or pages to a custom post type (or vice versa). You can limit the conversion to posts in a single category or children of specific page. You can also assign new taxonomy terms, which will be added to the posts’ existing terms.
This plugin is useful for converting many posts at once. If you’d rather do one at a time, use <a href="https://wordpress.org/extend/plugins/post-type-switcher/" rel="ugc">Post Type Switcher</a> instead.

Convert Post Types

Wordpress 4.9.5

No better plugin for converting categories to custom post types. And vice versa.

Still works great

A bulk conversion utility for post types.

netbiel

This plugin ads some extra options to your Customizer (like social icons), registers taxonomies and custom posts types for: 
– Portfolio items 
– Testimonials 
– FAQ 
– Team Members
This plugin doesn’t change how new post types are displayed in your theme. e.g You’ll need to add templates for archive-portfolio.php and single-portfolio.php if you want to customize the display of portfolio items. 
In the theme integrated with smartlib library you don’t need do anything

Smartlib Tools

Useful post types and customizer options.

Convert Post Types vs Smartlib Tools