The closest thing you're probably going to find for languages is the Pimsleur method, which is also based on a specific formula of spaced repetition. I don't k

The closest thing you're probably going to find for languages is the Pimsleur method, which is also based on a specific formula of spaced repetition. I don't know how effective it would be for trying to achieve true conversational fluency, but I've found it very effective for quickly learning a basic set of words and phrases for a trip to another country. https://www.pimsleur.com/ https://www.pimsleur.com/