Eigofy is a dictionary tool designed for Chrome that provides instant translations of subtitles from YouTube videos. This add-on enhances the viewing experience by allowing users to hover over English words in the subtitles to see their Japanese translations in a pop-up window when the "Shift" key is pressed.

In addition to instant translations, Eigofy offers features such as audio pronunciation through a speaker icon, enabling users to learn the correct pronunciation of words. Users can also save learned words for future reference, creating a personalized vocabulary list. Each term is accompanied by a star rating that indicates its frequency of use, helping learners prioritize their vocabulary acquisition based on usage frequency.