Lingo is a Chrome extension designed to facilitate the learning of English vocabulary through an engaging and user-friendly interface. It offers six free vocabulary books containing a total of 3,600 words, categorized for easy navigation. The application employs flashcard displays to optimize the learning process, allowing users to review and memorize new words effectively.

Key features include customizable review levels that adjust word repetition based on individual learning progress and a spaced repetition algorithm that enhances long-term memory retention. Lingo also supports multisensory learning by providing images, explanations, examples, and audio pronunciations for each word. With both dark and light modes available, users can select their preferred visual experience while tracking their learning progress through detailed statistics and charts.