Store Locator Plus uses the built-in WordPress internationalization and localization tools to translate the interface text into various languages. Store Locator Plus plug-in is part of the WordPress Translate project. You can contribute translations for the base plugin at the Store Locator Plus directory at WordPress Translate.
If you do not see the base plugin in your language, check the SLP Translate report for the latest Stable Release and make sure your language is at 100%. The Translate system will not create a language export for partial translations. If you want to help with the translation, send a request to be added to the WordPress PolyGlots project.
Learn About Translate.WordPress.Org.