This premium version of this plugin comes with several labelling options, which can be accessed by navigating to Settings > Labelling.
You can use these to either specify different wording for the various labels found in the plugin or to change them into a different language. If your site is only in one language, this is a quick and easy way to translate the Ultimate Product Catalog without the need to make use of third-party translation plugins.
Additionally, all of the strings in the plugin are localized, so it can definitely be used with a translation plugin should your use case require that. For more on that, see here.