Question: I need a language learning app that offers courses on multiple languages, including Japanese and Korean, and has a spaced repetition algorithm to help me remember words.

If you want a language learning app with courses in multiple languages, including Japanese and Korean, and spaced repetition to help you remember what you learned, Lingvist is a good choice. It's got more than 50 courses, and AI technology personalizes learning to focus on the vocabulary you're most likely to need in real-world situations. The app offers custom decks, spaced repetition and lessons that are broken down into bite-sized chunks that are adapted to your learning speed.

Another good option is SpeakAI, which offers personalized learning paths and interactive lessons in Chinese, English, Japanese, Korean, French, German, Italian and Spanish. It offers real-time grammar correction and real-time dialogue mode so you can have a conversation with a virtual partner, which is good for improving your pronunciation and fluency.

Retention is another option, particularly if you're an intermediate or advanced learner. It's designed to reinforce and expand what you already know with fast-paced exercises and uses AI to adapt to your language level. It's got a broad range of languages supported and a progress-tracking feature.

For a more complete approach, Mango covers more than 70 languages and is designed to help you build the core language skills of vocabulary, grammar and pronunciation. It's got a daily review system with personalized flashcards and native speaker audio to help you learn to communicate effectively through a conversation-based approach.