Write plugin/addin consistently
During translation it seems like perhaps different words are used to describe the same things.
plugin addin Add-In Add-in
Perhaps the same word an case should be used all places.
<title>Fixed Width Add-in</title> <p>The <app>Fixed Width</app> plugin allows ...
<figure><title><app>Gnote</app> Addin Preferences</title>
<title>Underline Text Add-In</title>