Nazmul Hossain Nihal

This allows user to add a widget that generates QrCode for every page dynamically. Whenever a visitor visits the site the widget will show qrcode for current page that the visitor is visiting. User can add the widget with and without title, define the size of the qrcode, fill color and background color. If the user finds that widget is not working because of any problem with theme user can add custom HTML tag before and after the widget. Multiple widgets can be added same time.
Using this you can add favicons to :
<ul>
<li>Add QrCodes</li>
<li>Customize QrCodes</li>
</ul>

WpQrCode

Just another WordPress plugin for adding QrCode.

Daniel

Provides a “Marker board” widget for visitors to play with. When a user’s mouse moves over the widget marker will be drawn on the surface.
The widget has four options, line color, line width, box width, and box height. Unfortunately html canvas requires explicit dimensions, the default dimensions for Markerboard are 150px by 150px.

WP Makerboard

Provides a "Marker board" widget for visitors to play with.

WpQrCode vs WP Makerboard