It works just perfect. The best!

Does perfect job

很好！簡單又方便快捷。

Does perfectly what it needs to do!

Easy way to transfer a url/textfield to a mobile device

Brilliantly simple, as how a URL QR code generator should be.

I also cannot express how much easier and pleasant it is to send links between separate ecosystems thanks to this (Windows --> iOS, in my case)

Nice addon, works also with actual Thunderbird - so it would be nice to add this also to TB addon page listing?

Works great! I just figured out how to save as an image on desktop: right-click the QR code, then go to the "Offline QR Code Generator" submenu, then "Save QR code as an image..."