Speak is a freemium language-learning application built on OpenAI's models, purpose-built to drive spoken fluency through AI-powered conversation practice. The core product architecture centers on real-time speech analysis — delivering pronunciation and phrasing feedback without human tutors in the loop. The curriculum follows a proprietary three-phase framework called the Speak Method (Learn → Practice → Apply). The Premium Plus tier exposes a fully personalized lesson engine that adapts to individual learner history and error patterns, including "Made for You" lessons and an unrestricted Speak Tutor experience. Speak is backed by the OpenAI Startup Fund and has reached 15M+ downloads with a 4.8-star rating, indicating large-scale production deployment.