It is a WordPress plugin that allows themes and other plugins to translate image size names into a readable form that is displayed using the Crop Thumbnails plugin.
Move the plugin folder to the wp-content/plugins/, activate the plugin in the admin panel of your site, and then use it in the code of other plugins and themes:
function translate_names($names) {
return array_merge($names, [
// your translations should be here... for example:
'your-image-size' => _( 'Home background' ),
'user-avatar' => _( 'Main profile photo ' ),
]);
}
add_filter( 'humanable_image_size_names', 'translate_names' );