Bi-Platform Spanish Learning Tool Development

We need an experienced engineer to develop an adaptive learning system for the Spanish Language which will function both on a website and mobile app. The system's primary outcome should focus on translation development. A vital feature for the tool would include a text-to-speech translation function. Ideally, candidates should have experience in edtech development and hold a strong proficiency in implementing language learning tools or features. Familiarity with speech recognition technology would also be of great value.