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.

prettyboymp

CMS Press opens up the ability to create and manage custom content types and taxonomies for your WordPress site. 
It adds the flexibility to have more than just posts and pages for content by allowing the user to register their 
own post_types that can use their separate theming from the post and page template along with its own permalink structure.
Along with custom post_types, CMS Press gives users the ability to register their own taxonomies. With the addition of 
custom taxonomies, a user can tag or categorize content separate from the default tags and categories.

CMS Press

Adds ability to create custom content types (post_types) and taxonomies to your WordPress installation.

Convert Post Types vs CMS Press