I added gettext support to the plugin.
Please look at the code: https://www.dropbox.com/s/9422hv0kzk3ogmx/wp-customer-reviews-gettext.zip
One Problem: In (my)
wp-customer-reviews-admin.php on line 510 my IDE shows an error. I am a frontend developer and no real php dev so I do not know how my changes broke the code there.
Take what you need from the code.
When the error is fixed I can test the changes and create the .pot file and set up the project at https://translate.foe-services.de