Open in Low Resolution checkbox on Retina MacBook Pro checked and disabled
It doesn't sound like the application actually supports HiDPI mode.  Here's a tutorial for modifying Microsoft Word's application package so it will support HiDPI Mode: http://imgur.com/a/0P5KY.  Perhaps it would work for this application as well.

Summary of the link:


Make a backup copy of the application
Open the application folder, then right click the app and choose "Show Package Contents"
Edit Contents/info.plist
Toward the bottom of the file, just before &lt;/dict&gt;, add the following lines:

&lt;key&gt;NSHighResolutionCapable&lt;/key&gt;
&lt;string&gt;True&lt;/string&gt;

Move the app package out of the applications folder.  Then move it back in.
The application may now allow a hacked, possibly glitchy retina mode.