These are the apps I used to become fluent in Chinese, one of the world's most difficult languages to learn

Du Chinese allows you to read through different Chinese stories, with the difficulty level ranging from beginner to advanced. The app's best feature is that tapping on a word reveals the pinyin and English translation. You can also save words to the app's flashcard deck or export them to a different flashcard app. The app's stories range from news articles and explanations of aspects of Chinese culture to horror stories and fairy tales.

Learning vocabulary in context is crucial for memorization and understanding how to use words, so this app has been part of my study routine for years. A subscription costs $15 a month.

Listening to Chinese music I love can always give me a boost when I'm feeling discouraged and unmotivated. While you can download Chinese music apps like Xiami or QQ from the App Store, Spotify may be better for beginner and intermediate learners, since Chinese apps can be difficult to navigate for non-fluent speakers.

There's lots of Chinese music on Spotify, but if you don't know where to start, check out No Party for Cao Dong's 如常 and 情歌; the indie band Wu Tiao Ren's 晚上好春天小姐 and 梦幻丽莎发廊; as well as Wu Bai's classic 挪威的森林. Spotify Premium costs $10 a month.

I recommend looking up a side-by-side English and Chinese translation of songs if you don't understand the lyrics. Sixth Tone also has a music section that can help you discover new artists to listen to.

Youku is a popular Chinese streaming service with Chinese dramas, documentaries, and comedies. Chinese language TV shows and movies are also available on American streaming platforms like Netflix, which has the movie "Tigertail" and the period drama, "Ghost Bride." Youku is free to download.

While reading the news in Mandarin might be too difficult for beginners, it can be a great tool to pick up relevant vocabulary and commonly used sentence structures for more advanced learners. The New York Times translates many of its articles into Chinese (a digital subscription to the NYT costs $5 a week), but you can access several free articles every month. VOA Mandarin (美国之音）is another free app with short news articles in Mandarin.

FluentU offers videos in nine different languages (including Mandarin) with subtitles that can help you develop listening and comprehension skills. The app also offers interactive videos and quizzes. You can get a free two-week trial, and after that it costs $20 a month.

For me, the most invaluable app for learning Chinese has been Pleco. The dictionary function allows you to look up Chinese characters by pinyin, the English word, or by writing the characters. Since Chinese characters often have meanings that can vary wildly based on context, Pleco's result page is comprehensive and offers example sentences as well as the English definition and pinyin.

One of Pleco's best features is that you can save words you look up in the dictionary into a flashcard deck, which makes it easy to integrate a word you've learned into regular study. The flashcard decks also use spaced repetition, a system where the app will show you a card more often or less often based on how well you remember it. You can also download additional functions like a document reader for an extra cost.

Pleco requires a one-time $30 payment.