We do not recommend "language learning" apps like Duolingo, Lingodeer, Babbel, and others due to the fact that their methodology conflicts with AJATT's principles of immersion learning. Such apps do not actually help you with anything. There are no success stories. On the other hand, AJATTers typically reach fluency in just 18 months. The apps prevent you from reading interesting content in your target language, such as manga. And they make you more miserable in the end.
To elaborate, apps such as Duolingo are not designed in a way that aligns with AJATT methodology. They reinforce traditional learning habits, which are not efficient. AJATT says that the most effective method of learning a foreign language is to surround yourself with the language as much as possible. We call this immersion. Immersion can be practiced through various activities, such as watching Japanese TV shows and movies, reading Japanese manga and books, and so on. In contrast, phone apps for learning Japanese typically rely on repetitive exercises and memorization drills, which are ineffective in helping learners achieve fluency in the language. Instead of immersion, Duolingo and such force the learner to produce sentences from the provided words and grammar rules, and memorize vocabulary in a specific order. Trying to produce language before it has been acquired naturally from input only creates disaster. Duolingo doesn't offer any input which is essential for acquiring a language. To make things worse, the whole process is accompanied by low-quality translations and robotic text-to-speech audio.
One of the key advantages of the AJATT method is that it enables learners to acquire the language naturally, just like how children learn their first language. This means that learners are exposed to the language in context, and they gradually develop an intuitive understanding of its nuances and grammar rules. On the other hand, relying solely on apps doesn't activate the natural process of language acquisition, making it difficult to apply what has been learned in real-life situations. At best one will have memorized some detached information, such as words and grammar, but will have no ability to use it properly.
Rather than just completing various drills, lessons or exercises, AJATT promotes engagement with the language on a personal level. Learners are encouraged to find immersion materials that interest them, choose compelling content, engage with the language in a way that is fun. AJATT enables you to learn from any type of media you want. This makes the learning process more enjoyable and motivating, leading to better retention and progress. In contrast, Duolingo has a high dropout rate because it is incredibly boring and tedious. No one likes their lessons. It even has to utilize a notification system to retain some users for a little longer.
With the AJATT method, the target language is learned strictly from native content, content crated by natives for natives. Listening to native speakers is crucial to learn how to sound natural when speaking. Duolingo is the opposite of being native. The text-to-speech software Duolingo uses is simply awful. Mistakes, mistakes, mistakes. They are everywhere. It pronounces Japanese incorrectly. The pitch accent is totally wrong. Correctly answered questions are counted as incorrect, or vice versa.
Duolingo teaches you very basic and primitive language. The maximum skill that one can achieve on Duolingo can be surpassed in just two or three months of doing AJATT properly.
Some say that you should only use Duolingo for learning kana and then quit. But I don't get that idea because there are better ways to learn kana.