Interface in russian for https://www.skipper18.com
You will only need to downlad the texts_ru.qm file containing the released translations. Save this file to the defined Skipper directory: Operating system language files location OS X */Skipper.app/Contents/MacOS Windows, Linux anywhere in the Skipper directory
Details - https://help.skipper18.com/how-to-use/application-concepts/localization