Paolo Bertinetti

QRMemo is a versatile WordPress plugin that enables you to automatically generate and display QR codes at the end of specific post types. The QR codes added automatically contain the URL of the page or post they are appended to, making it easy for users to share or save the page.
The plugin also supports generating QR codes using a shortcode, allowing you to insert a QR code with custom text anywhere in your content.
Key Features: 
* Automatically add QR codes containing the page URL to the end of posts, pages, and other custom post types. 
* Customize which post types should display QR codes. 
* Generate QR codes via shortcode, specifying custom text, size, margin, and alignment.
Libraries Used: 
* <a href="https://github.com/endroid/qr-code" rel="nofollow ugc">Endroid QR Code</a> – A powerful library for generating QR codes in PHP.
<h3>License</h3>
This plugin is licensed under the GPLv2 or later. For more details, see <a href="https://www.gnu.org/licenses/gpl-2.0.html" rel="nofollow ugc">https://www.gnu.org/licenses/gpl-2.0.html</a>.

QRMemo

QRMemo is a WordPress plugin that adds QR codes to the end of selected post types and allows generating QR codes via shortcode.

Amaury Balmer

WordPress 3.1 and up allow to manage new custom post type, this plugin makes it even simpler, removing the need for you to write any code. Excerpt update your theme !
This plugin provides a nice interface and easy access. The plugin provides almost all the parameters of the WordPress CPT API.
It’s possible to manage the permissions of custom post types such as articles or pages. Or create a full set of custom permissions and related roles !
This plugin is developped on WordPress 3.3, with the constant WP_DEBUG to TRUE.

Simple Custom Post Types

WordPress 3.1 and up allow to manage new custom post type, this plugin makes it even simpler, removing the need for you to write any code.

QRMemo vs Simple Custom Post Types