Funk Design

The DQRS (DynamicQRSaver) generates a dynamic QR-Code. This QR-Code / the URL gets saved in the WordPress-Database and can be changed later on. 
Simply edit the QR-Code URL in the Backend-Tab.
<h3>Arbitrary section</h3>
Visit the developer and designer of this awsome plugin at <a href="http://funk.design/" title="Your favorite webdesigner" rel="nofollow ugc">Funk.design</a>

Dynamic QR Code URL Saver

Idea is great because so many dead liks are the and some qr codes will e printed as well.

I red that pretty links offer this but can't find this option there.
I would love to have an export there and best case directly from post editor ;)

I would like to believe the best ;)

Generates a dynamic QR-Code, which can be saved and edited later, even if the QR Code was printed. Very easy to install and use. Share smartly!

Jrack Wolfe

Displays at QR code dynaically on a page or post with URL to that page/post.
There are many QR generators that are avialable for use. Most of these, however, are accessbile via the admin dashboard so you can create site QR codes as media files for download. This plugin also does that but goes one step further – it allows you to use shortcode to dynamically generate a QR code for the page or post being displayed.
Wolfe Candy QR Code Generator is part of the Wolfe Candy suite of plugins that all work together to make <a href="https://wordpress.org/" title="Your favorite software" rel="ugc">WordPress</a> site creation that much easier. The QR code generator works particularly well with the Wolfe Candy S3 Gallery.
Major features include:
<ul>
<li>This dynamically generates a QR code in the front-end for the page or post that is being displayed via shortcode.</li>
<li>This plugin uses the standard PHP generator library so it can also generate a QR code to a file.</li>
<li>It can also generate a QR code for any data text via shortcode.</li>
<li>Alter size, error correction and pixel scale via shortcode arguments.</li>
<li>It is a simple QR code generator so does not support different color styles and logos – it just does what is needs to do.</li>
</ul>
It is completely FREE – development and maintenance by the Wolfe Candy team headed by Jrack Wolfe is funded through <a href="https://www.paypal.com/donate/?hosted_button_id=DY2RMD3J4SR3Q" title="Donate to Wolfe Candy" rel="nofollow ugc">donations</a> from generous users.

Wolfe Candy QR Code Generator

Displays at QR code dynaically on a page or post with URL to that page/post.

Dynamic QR Code URL Saver vs Wolfe Candy QR Code Generator