The official website of Ecuakaraoke (ecuakaraoke.com) seems to be in Spanish and might offer a free trial or demo version. However, I couldn't verify if they provide a full free download.
If you are looking for specific installers or legacy versions (like the 2014 edition), some archival sites host documentation and links: descargar ecuakaraoke full gratis link
Si aún así decides seguir buscando, al menos hazlo con inteligencia: The official website of Ecuakaraoke (ecuakaraoke