Hi Alessandro,
First of all thanks for using my plugin, please show your love at the place where it is meant for!
To come back on you request. This plugin outputs the ‘default stuff’ so it’s useful for all kind of projects, styling etc. However what stops you? You can customise the widget by copying the folder ‘dd_templates’ from the plugin folder to your theme folder and add it by yourself inside the ‘lastviewed-widget.php template.
Good luck with it, you can do it! Thanks already for the review ?? and offcourse for using my plugin.
I close this tickets because it’s not a bug and can be solved by using the build in customisation part.
Wouter